th105 FoCARSFoundation Course For Agricultural Research Service

Digital Repository of Course Materials

• Computer Peripherals and Internet

• Guidelines for Digital Presentations

• Overview of Multimedia

• Video in Agricultural Research and Education

• Geographical Information Systems Concepts

• An Overview of Database Management

Course Coordinators K. Kareemulla and S. Ravichandran

Support Team P. Krishnan and P. Namdev

1

COMPUTER PERIPHERALS AND

INTERNET

M.Balakrishnan1 and G.R.K.Murthy

2

Introduction

A computer peripheral is a device that is connected to a computer but is not

part of the core computer architecture. The core elements of a computer are

the central processing unit, power supply, motherboard and the computer

case that contains those three components. Technically speaking, everything

else is considered a peripheral device. However, this is a somewhat narrow

view, since various other elements are required for a computer to actually

function, such as a hard drive and random-access memory (or RAM).

Most people use the term peripheral more loosely to refer to a device

external to the computer case. You connect the device to the computer to

expand the functionality of the system. For example, consider a printer.

Once the printer is connected to a computer, you can print out documents.

Another way to look at peripheral devices is that they are dependent on the

computer system. For example, most printers can't do much on their own,

and they only become functional when connected to a computer system.

Types of Peripheral Devices

There are many different peripheral devices, but they fall into three general

categories:

Input devices, such as a mouse and a keyboard

Output devices, such as a monitor and a printer

Storage devices, such as a hard drive or flash drive

Some devices fall into more than one category. Consider a CD-ROM drive;

you can use it to read data or music (input), and you can use it to write data

to a CD (output). Peripheral devices can be external or internal. For

1 Principal Scientist, ICM Division, NAARM

2 Principal Scientist, ESM Division, NAARM

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example, a printer is an external device that you connect using a cable,

while an optical disc drive is typically located inside the computer case.

Internal peripheral devices are also referred to as integrated peripherals.

When most people refer to peripherals, they typically mean external ones.

The concept of what exactly is 'peripheral' is therefore somewhat fluid. For

a desktop computer, a keyboard and a monitor are considered peripherals -

you can easily connect and disconnect them and replace them if needed. For

a laptop computer, these components are built into the computer system and

can't be easily removed. The term 'peripheral' also does not mean it is not

essential for the function of the computer. Some devices, such as a printer,

can be disconnected and the computer will keep on working just fine.

However, remove the monitor of a desktop computer and it becomes pretty

much useless.

Central Processing Unit - Though the term relates to a specific chip or

the processor a CPU's performance is determined by the rest of the

computer's circuitry and chips.

Currently the Pentium chip or processor, made by Intel, is the most

common CPU though there are many other companies that produce

processors for personal computers. Examples are the CPU made by

Motorola and AMD.

With faster processors the clock speed becomes more important.

Compared to some of the first computers which operated at below

30 megahertz (MHz) the Pentium chips began at 75 MHz in the late

1990's. Speeds now exceed 3000+ MHz or 3 gigahertz (GHz) and

different chip manufacturers use different measuring standards (check

your local computer store for the latest speed). It depends on the circuit

board that the chip is housed in, or the motherboard, as to whether you

are able to upgrade to a faster chip. The motherboard contains the circuitry

and connections that allow the various components to communicate with

each other.

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Though there were many computers using many different processors

previous to this I call the 80286 processor the advent of home computers

as these were the processors that made computers available for the average

person. Using a processor before the 286 involved learning a proprietary

system and software. Most new software is being developed for the newest

and fastest processors so it can be difficult to use an older computer

system.

Motherboard and Processor

An experience with PC depends on a combination of the processor, the

memory, the motherboard, the graphics and sound components and the

hard disk that the PC has. The first two things to consider when buying a

PC are the motherboard and the processor, which are interdependent. A

particular processor only goes on a particular kind of motherboard. For

each kind of motherboard, there might be different brands available, with

different features. It is better to choose processor and then decide brand of

motherboard, based on its features.

Motherboard

The motherboard is the base of a PC—all the components fit on it. It also

has a master brain called the chipset which decides what will work and

how. The motherboards contains 3 essential parts: Concept Map of

Motherboards and main components

Expansion Capabilities

CPU (Processor)

RAM (Memory)

Nearly all modern motherboards will contain one or more expansion slots.

The most common type of slot is the PCI slot, which is used for peripherals

such as TV Tuners, Network Cards, and USB/Firewire Cards. The next

most common expansion slot is the PCIe, or PCI Express, which is nearly

always used for video cards.

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Of course nothing in the computer can work without the processing power

of the CPU. Intel is the largest manufacturer of these in the world. This is

the part that is referred to when you hear the ads "Intel Inside". The

processor is measured by the speed at which it operates, or gigahertz. It is

essential when picking a processor that a pin-compatible motherboard is

also selected.

The final essential addition to a motherboard is memory, or RAM. Memory

is where programs and data reside when you are working on them. It also

holds the data for the processor until it is ready to use it. The more memory

there is in the computer, the more data it can hold and work on at one time.

This means that you can have more programs and files open at once without

the computer slowing down. The motherboard is chosen based on

Processor: The processor sits on a main board called the motherboard, in a

particular slot or socket. This slot determines which processor will go on

the motherboard.

Graphics: Onboard graphics Motherboards can also be chosen based on

whether they have integrated graphics on them or not. The earlier graphics

cards used to be PCI cards (fitting on the PCI slot on the motherboard).

Later something called the Accelerated Graphics Port, or AGP was

developed especially for graphics cards and made graphics faster. There

are motherboards that had graphics capabilities built into them. However,

the graphics from these are only good enough for browsing, Word, Excel,

etc, not for heavy 3D games or graphics. The Intel 810 chipset come with

onboard graphics, and are a real money saver. For serious gaming and

graphics, we need the AGP slot to be there on the motherboard, and add a

graphics card to it. The Intel 815 chipset based motherboards come with

onboard graphics, but also have an AGP slot on them, so we can go with

onboard graphics initially and get a good graphics card later. The new P4s

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go on the Intel 850 chipset based motherboards, which have a slot for

RDRAM memory modules, and an AGP slot. Look for the number of slots

for add-on cards. Apart from the AGP slot, look for the number of PCI

slots on the board for- internal modem, TV tuner/video capture cards and

other accessories.

Look for the number of RAM slots and how much RAM it can take. Some

new motherboards have slots to take even 2 GB of RAM.

Buses

A bus is a subsystem that transfers data between computer components

inside a computer or between computers. Unlike a point-to-point

connection, a bus can logically connect several peripherals over the same set

of wires. Each bus defines its set of connectors to physically plug devices,

cards or cables together. There are two types of buses: internal and external.

Internal buses are connections to various internal components. External

buses are connections to various external components. There are different

kinds of slots that internal and external devices can connect to.

Processor

The processor, which is the brain of a PC, is often chosen with price as the

main criteria, but changing the processor often means changing the

motherboard. The other extreme, when the budget is unlimited, is to

scramble for the latest, fastest processor. There will always be a faster one

just around the corner but it should not be exceedingly beyond our

requirements, say if our applications are simply writing documents in

Word, browsing the Net and sending and receiving e-mail. Choose the

processor keeping in mind our activities on the PC, but don‟t be stingy

either. Both the processor as well as motherboard should be chosen

keeping in mind the fact that they‟re both very tough to upgrade—because

they‟re expensive and when we change them, we have to change a lot of

things along with them, almost like overhauling the PC.

Types of Processors

Pentium and AMD processor are some of the processor options. AMD

processors have been around for a long time. The processors that made an

impact in recent times are the Duron and the Athlon. Intel has the value

option, Celeron and the high-performance processor, P4, while AMD has

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Duron for value proposition and Athlon for high-end one. Nowadays,

processors are coming in as dual core which is a CPU with two separate

cores on the same die, each with its own cache. It's the equivalent of

getting two microprocessors in one. A dual-core processor uses slightly

less power than two coupled single-core processors, principally because of

the increased power required to drive signals external to the chip and

because the smaller silicon process geometry allows the cores to operate at

lower voltages; such reduction reduces latency.

Most of the processors are in 32-bit. This is the number of bits that can be

processed in parallel. Or the number of bits used to represent a single

element in a data format. Future software is going to be available in 64 bit

format increasingly.

Realities of bits in Processors

A 32 bit CPU can process 32 bits of data at a time. If data has

more than 32 bits, processor takes up „32‟ bits of data first and

processes it and then next group of „32‟ bits of data is taken up

for processing

Hence a 64-bit CPU performs better than a 32 bit processor

64 bit is very useful for 3d animators, game developers,

CAD/CAM engineers, automobile manufacturers

A 32 bit CPU can access only 4 GB (232 ) of main memory

while a 64 bit CPU can address up to 17 billion GB which is

more than enough for any present and near future application

A 64 bit CPU needs 64 bit OS and 64 bit applications to deliver

optimum results. Some 64 bit CPUs allows running 32 bit

applications and OS but it is a point of under utilization.

A 64 bit processor doubles the bandwidth with the processor

core while dual core gives 2 processor cores inside a single

processor. A 64 bit is like fitting a car with a more powerful

engine while a dual core is fitting the same with 2 engines

which may or may not be as powerful as the replaced one.

The entry level is 915 chipset while others include 925,945 and

955 chipsets.

945 and 955 based chipsets support dual core processors

(called Pentium D).

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Internal

Types of Slots

There are many different kinds of internal buses, but only a handful of

popular ones. Different computers come with different kinds and number of

slots. It is important to know what kind and number of slots you have on

your computer before you go out and by a card that matches up to a slot you

don‟t have.

PCI

PCI (Peripheral Component Interconnect) is common in modern PCs. This

kind of bus is being succeeded by PCI Express. Typical PCI cards used in

PCs include: network cards, sound cards, modems, extra ports such as USB

or serial, TV tuner cards and disk controllers. Video cards have outgrown

the capabilities of PCI because of their higher bandwidth requirements.

PCI Slots

PCI Express

PCI Express was introduced by Intel in 2004. It was designed to replace the

general-purpose PCI expansion bus and the AGP graphics card interface.

PCI express is not a bus but instead a point-to-point connection of serial

links called lanes. PCI Express cards have faster bandwidth then PCI cards

which make them more ideal for high-end video cards.

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PCMCIA

PCMCIA (also referred to as PC Card) is the type of bus used for laptop

computers. The name PCMCIA comes from the group who developed the

standard: Personal Computer Memory Card International Association.

PCMCIA was originally designed for computer memory expansion, but the

existence of a usable general standard for notebook peripherals led to many

kinds of devices being made available in this form. Typical devices include

network cards, modems, and hard disks.

AGP

AGP (Accelerated Graphics Port) is a high-speed point-to-point channel for

attaching a graphics card to a computer‟s motherboard, primarily to assist in

the acceleration of 3D computer graphics. AGP has been replaced over the

past couple years by PCI Express. AGP cards and motherboards are still

available to buy, but they are becoming less common.

AGP Slot

Hard Disk

When dealing with storage space required for the programs and files,

space and speed matter. 40 GB hard disks are common and adequate. As

the capacity increases, the cost per unit memory reduces. If we need to

frequently transport lots of data to office and back, USB hard disk is

better. These are mobile hard disks and have a flash RAM that can be

connected to the USB port to store data in capacities of 16, 32, 64, 128

MB and 6 GB, 20 GB. The price range starts from Rs 3,000. A 40 GB

5400 rpm disk costs Rs 4,500. Some brands available in the market are

Samsung, Seagate, Maxtor, and Western Digital.

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Features of a hard disk

i. The interface speed: All recent model motherboards and hard disks

support the IDE/ATA interface. For those who need to work with huge

files at blazing speeds, a SCSI hard disk is the best option. But this will

require a SCSI host adapter. The IDE/ATA interface available now is rated

at 100 Mbps. But a faster interface alone won‟t have a great bearing on the

performance. The controller too has to support it. That‟s where your

motherboard specs come in.

ii. Spindle speed: The faster the speed, better the performance, ranging

from 5400 rpm to 7200 rpm for ordinary purposes. For video rendering

sort of work, go for higher speeds or opt for SCSI drives that offer even

10000 to 15000 rpm speeds.

iii. Seek time: This is measured in milliseconds. How quickly can the disk

store or retrieve data influences the disk performance. The lesser they seek

time, the faster the disk performance.

Nowadays hard disks are coming with faster spindle speeds, larger caches,

better reliability, and increased data transmission speeds. IDE is the

commonly used hard disk. New standard known as Serial ATA (Serial

Advanced Technology Attachment) is around now and is destined to

become “the standard”.

Tips for better disk management

Partition

defragment

remove temporary files (files with extension .tmp)

check for bad sectors

remove unused programs regularly

regularly scan for viruses

protect the data and

be organized

Input

Input devices are absolutely crucial to computers. The most common input

devices are mice and keyboards which barely every computer has. A new

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popular pointing device that may eventually replace the mouse is touch

screen which you can get on some tablet notebooks. Other popular input

devices include microphones, webcams, and fingerprint readers which can

also be built in to modern laptops and desktops. A scanner is another

popular input device that might be built-in to your printer.

Keyboard - The keyboard is used to type information into the computer

or input information. There are many different keyboard layouts and sizes

with the most common for Latin based languages being the QWERTY

layout (named for the first 6 keys). The standard keyboard has 101 keys.

Notebooks have embedded keys accessible by special keys or by pressing

key combinations (CTRL or Command and P for

example). Ergonomically designed keyboards are designed to make

typing easier. Hand held devices have various and different keyboard

configurations and touch screens.

Some of the keys have a special use. They are referred to as command

keys. The 3 most common are the Control or CTRL, Alternate or Alt and

the Shift keys though there can be more (the Windows key for example or

the Command key). Each key on a standard keyboard has one or

two characters. Press the key to get the lower character and hold Shift to

get the upper.

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Removable Storage and/or Disk Drives

The same kinds of CD and DVD drives that could come built-in on your

computer can also be attached externally. You might only have a CD-

ROM drive built-in to your computer but you need a CD writer to burn

CDs. You can buy an external CD writer that connects to your USB port

and acts the same way as if it was built-in to your computer. The same is

true for DVD writers, Blu-ray drives, and floppy drives. Flash drives have

become very popular forms of removable storage especially as the price of

flash drives decreases and the possible size for them increases. Flash

drives are usually USB ones either in the form USB sticks or very small,

portable devices. USB flash drives are small, fast, removable, rewritable,

and long-lasting. Storage capacities range from 64MB to 32GB or more. A

flash drive does not have any mechanically driven parts so as opposed to a

hard drive which makes it more durable and smaller usually.

Non-removable Storage

Non-removable storage can be a hard drive that is connected externally.

External hard drives have become very popular for backups, shared drives

among many computers, and simply expanding the amount of hard drive

space you have from your internal hard drive. External hard drives come

in many shapes and sizes like flash drives do. An external hard drive is

usually connected by USB but you can also have a networked hard drive

which will connect to your network which allows all computers on that

network to access that hard drive.

Digital flash drives work slightly differently as they use memory

cards to store information so there are no moving parts. Digital cameras

also use Flash memory cards to store information, in this case

photographs. Hand held devices use digital drives and many also use

removable or built in memory cards.

USB Flash Drive

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Mouse - Most modern computers today are run using a mouse controlled

pointer. Generally if the mouse has two buttons the left one is used

to select objects and text and the right one is used to access menus. If the

mouse has one button (Mac for instance) it controls all the activity and a

mouse with a third button can be used by specific software programs.

One type of mouse has a round ball under the

bottom of the mouse that rolls and turns two

wheels which control the direction of the pointer

on the screen. Another type of mouse uses an

optical system to track the movement of the

mouse. Laptop computers use touch pads, buttons

and other devices to control the pointer. Hand

helds use a combination of devices to control the

pointer, including touch screens.

Note: It is important to clean the mouse periodically, particularly if it

becomes sluggish. A ball type mouse has a small circular panel that can be

opened, allowing you to remove the ball. Lint can be removed carefully

with a tooth pick or tweezers and the ball can be washed with mild

detergent. A build up will accumulate on the small wheels in the mouse.

Use a small instrument or finger nail to scrape it off taking care not to

scratch the wheels. Track balls can be cleaned much like a mouse and

touch-pad can be wiped with a clean, damp cloth. An optical mouse can

accumulate material from the surface that it is in contact with which can

be removed with a finger nail or small instrument.

Output

There are lots of different kinds of output devices that you can get for your

computer. The absolute most common external output device is a monitor.

Other very popular output devices are printers and speakers. There are lots

of different kinds of printers and different sizes of speakers for your

computer. Monitors are connected usually through the HD-15 connector

on your video card. Printers are usually connected through a USB port.

Speakers have their own audio out port built-in to the sound card.

Monitors - The monitor shows information on the screen when you type.

This is called outputting information. When the computer needs more

information it will display a message on the screen, usually through

a dialog box. Monitors come in many types and sizes. The resolution of

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the monitor determines the sharpness of the screen. The resolution can be

adjusted to control the screen's display.

Monitor

Most desktop computers use a monitor with a cathode tube or liquid

crystal display. Most notebooks use a liquid crystal display monitor.

To get the full benefit of today's software with full colour graphics and

animation, computers need a colour monitor with a display

or graphics card.

Printers - The printer takes the information on your screen and transfers it

to paper or a hard copy. There are many different types of printers with

various levels of quality. The three basic types of printer are; dot

matrix, inkjet, and laser.

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Dot matrix printers work like a typewriter transferring ink from a

ribbon to paper with a series or 'matrix' of tiny pins.

Ink jet printers work like dot matrix printers but fire a stream of ink

from a cartridge directly onto the paper.

Laser printers use the same technology as a photocopier using heat

to transfer toner onto paper.

Modem - A modem is used to translate information transferred through

telephone lines, cable, satellite or line-of-sight wireless.

The term stands for modulate and demodulate which changes the signal

from digital, which computers use, to analog, which telephones use and

then back again. Digital modems transfer digital information directly

without changing to analog.

Modems are measured by the speed that the information is transferred. The

measuring tool is called the baud rate. Originally modems worked at

speeds below 2400 baud but today analog speeds of 56,000 are standard.

Cable, wireless or digital subscriber lines can transfer information much

faster with rates of 300,000 baud and up.

Modems also use Error Correction which corrects for transmission errors

by constantly checking whether the information was received properly or

not and Compression which allows for faster data transfer rates.

Information is transferred in packets. Each packet is checked for errors

and is re-sent if there is an error.

Anyone who has used the Internet has noticed that at times the information

travels at different speeds. Depending on the amount of information that is

being transferred, the information will arrive at its destination at different

times. The amount of information that can travel through a line is limited.

This limit is called bandwidth.

There are many more variables involved in communication technology

using computers, much of which is covered in the section on the Internet.

Scanners- Scanners allow you to transfer pictures and photographs to your

computer. A scanner 'scans' the image from the top to the bottom, one line

at a time and transfers it to the computer as a series of bits or a bitmap.

You can then take that image and use it in a paint program, send it out as a

fax or print it. With optional Optical Character Recognition (OCR)

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software you can convert printed documents such as newspaper articles to

text that can be used in your word processor. Most scanners

use TWAIN software that makes the scanner accessible by other software

applications.

DIGITAL CAMERA

Digital cameras allow you to take digital photographs. The images are

stored on a memory chip or disk that can be transferred to your computer.

Some cameras can also capture sound and video.

Digital camera comes with accessories like a

Battery pack, Digital cameras consume more power than the film-

based cameras do, plus they have the added power consumption of

the LCD preview screen. So it‟s very important that they have

enough power to last a good number of shots. It‟s very important

that the battery be rechargeable

a memory card, The 8 MB, 16 MB memory cards that come with

camera are just not good enough. Buy an extra 32 or 64 MB card.

Floppy-based cameras are also available.

an AC power adapter and

Something to connect camera to the PC.

Case - The case houses the microchips and circuitry that run the computer.

Desktop models usually sit under the monitor and tower models beside.

They come in many sizes, including desktop, mini, midi, and full tower.

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There is usually room inside to expand or add components at a later time.

By removing the cover off the case you may find plate covered empty

slots that allow you to add cards. There are various types of slots including

IDE, ASI, USB, PCI and Firewire slots.

Depending on the type notebook computers may have room to expand.

Most Notebooks also have connections or a port that allows expansion or

connection to exterior, peripheral devices such as monitor, portable hard-

drives or other devices.

Web Camera

Webcams are used to take snapshots or record short video clips which you

can then send by e-mail to friends and relatives around the world. Another

cool place where Webcams can be put to use is video chat which lets us

actually see the person we are chatting with.

Some of the Webcams available are

Vcam Eye for PC

IBM PC Camera

Logitech QuickCam Home

NetView PC Camera

Kensington VideoCAM

Creative WebCam Go Plus

Kensington VideoCAM Super VGA

Logitech QuickCam Pro

Cards - Cards are components added to computers to increase their

capability. When adding a peripheral device makes sure that your

computer has a slot of the type needed by the device.

Sound cards allow computers to produce sound like music and voice. The

older sound cards were 8 bit then 16 bit then 32 bit. Though the human ear

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can't distinguish the fine difference between sounds produced by the more

powerful sound card they allow for more complex music and music

production.

Sound Cards

Graphic cards allow computers to produce

colour (with a colour monitor of course). The

first colour cards were 2 bit which produced 4

colours [CGA]. It was amazing what could be

done with those 4 colours. Next came 4 bit

allowing for 16 [EGA and VGA] colours. Then came 16 bit allowing for

1064 colours and then 24 bit which allows for almost 17 million colours

and now 32 bit and higher allow monitors to display almost a billion

separate colours.

Video cards

Video cards allow computers

to display video and

animation. Some video cards

allow computers to display

television as well as

capture frames from video. A

video card with a digital video

camera allows computers users to produce live video. A high speed

connection is required for effective video transmission.

Network Card

Network cards allow computers to

connect together to communicate

with each other. Network cards have

connections for cable, thin wire or

wireless networks. For more

information see the section on

Networks.

Cables connect internal components

to the Motherboard, which is a

board with series of electronic path ways and connections allowing

the CPU to communicate with the other components of the computer.

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Cables

Memory - Memory can be very confusing but is

usually one of the easiest pieces of hardware to

add to your computer. It is common to

confuse chip memory with disk storage. An

example of the difference between memory and

storage would be the difference between a table

where the actual work is done (memory) and a filing cabinet

where the finished product is stored (disk). To add a bit more confusion,

the computer's hard disk can be used as temporary memory when the

program needs more than the chips can provide.

Random Access Memory or RAM is the memory that the computer uses

to temporarily store the information as it is being processed. The more

information being processed the more RAM the computer needs.

One of the first home computers used 64 kilobytes of RAM memory

(Commodore 64). Today's modern computers need a minimum of 64 Mb

(recommended 128 Mb or more) to run Windows or OS 10 with modern

software.

RAM memory chips come in many different sizes and speeds and can

usually be expanded. Older computers came with 512 Kb of memory

which could be expanded to a maximum of 640 Kb. In most modern

computers the memory can be expanded by adding or replacing the

memory chips depending on the processor you have and the type of

memory your computer uses. Memory chips range in size from 1 MB to 4

GB. As computer technology changes the type of memory changes as well

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making old memory chips obsolete. Check your computer manual to find

out what kind of memory your computer uses before purchasing new

memory chips.

iPod

iPod is a brand of portable media players designed and marketed by Apple

Computer. It stores media on a built-in hard drive, while the smaller iPod

use flash memory (ie., with additional memory). It functions as a mass

storage device for storage of user files and can transfer files from and to

computer using its memory. With an iPod, there is no need of carrying

bulky floppies/ CDs for carrying data and presentations outside. It works

on Mac and Windows (present models) platforms. We can keep track of

meetings, schedules, deadlines to meet targets, organize our activities

using an iPod.

With time, iPods are evolved considering the features of

Lighter weight

Smaller size

color displays

Video playing

Extendable memory

Platform

compatibility

The present models

available are iPod (to play

audio), iPod nano (to play

audio and view images) and iPod video (to play audio, video and images).

iPad

The iPad is a 9.7 inch touch screen tablet PC made by Apple. The iPad is

basically a netbook without a keyboard. It has a multi-touch LED-backlit

9.7 x 7.5 inch front display and weighs 1.5 pounds, with a battery that lasts

up to ten hours

The iPad is the only one of the three that is a proper tablet.

It is available with Wi-Fi only or with Wi-Fi and 4G.

25cm screen (the largest of all three).

Available with 16GB, 32GB or 64GB.

Up to 10 hours of battery life (based on watching videos and

listening to music).

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iPhone

iPhone is a Smartphone made by Apple that combines an iPod, a tablet

PC, a digital camera and a cellular phone. The device includes Internet

browsing and networking capabilities.

The iPhone is the only one of the three that can be used as a phone.

It is available with Wi-FI and 3G (and 4G depending on the

model).

Comes with a built in GPS receiver (needed for satellite

navigation).

iPhone comes with Siri - a voice activated intelligent assistant.

9cm screen.

Available with 16GB, 32GB or 64GB.

With an iPhone 5S there's 10 hours of video playback, 40 hours of

audio playback or 10 hours of talk time on 3G.

Smartwatch(iWatch)

Apple Watch is a line of smartwatches developed by Apple Inc. It

incorporates fitness tracking and health-oriented capabilities with

integration with iOS and other Apple products and services.

The watch has a completely new user interface, different from the

iPhone, and the 'crown' on the Apple Watch is a dial called the

'digital crown.„

Users can turn the crown to zoom in and out on a map, or scroll a

list.

The crown can also be pressed to take the user back to the home

screen.

Different areas on the watch face can be customized with taps and

swipes, and force touches

Users can also talk to the watch and send a voice reply, or have it

transcribed to them.

There is no keyboard on the watch, and messages can only be sent through

dictation, or emoji

Apple TV

It might have escaped the attention of many people that 2017 actually

marks the 10th anniversary of Apple TV. With this in mind some think

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that Apple could celebrate the occasion with an update to its little black

box. Whether this is true or not remains a mystery, as there have been very

few credible rumours about any new developments inside the Apple

campus. Then there's also the fact that the usual gap between iterations of

Apple TV tends to be two or three years.

It was curious though that a large section of the recent WWDC event was

given to the software updates in tvOS.

Networks and Internet

What is a network?

The generic term "network" refers to a group of entities (objects, people,

etc.) which are connected to one another. A network, therefore, allows

material or immaterial elements to be circulated among all of these

entities, based on well-defined rules.

Network: A group of computers and peripheral devices connected

to each other. Note that the smallest possible network is two

computers connected together.

Networking: Implementing tools and tasks for linking computers

so that they can share resources over the network.

Depending on what kind of entity is involved, the term used will differ:

Transportation network: A combination of infrastructure and

vehicles used for transporting people and goods between different

geographic areas.

Telephone network: Infrastructure for transporting voice signals

from one telephone station to another.

Neural network: A group of brain cells connected to each other

Criminal network: A group of con artists in cahoots (wherever

there's one con artist, there's usually another!)

Computer network: A group of computers linked to each other

with physical lines, exchanging information as digital data (binary

values, i.e. values encoded as a signal which may represent either 0

or 1)

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Why networks are important

A computer is a machine used to manipulate data. Humans, being

communicative creatures, quickly understood why it would be useful to

link computers to each other in order to exchange information.

A computer network can serve several distinct purposes:

Sharing resources (files, applications or hardware, an Internet

connection, etc.)

Communication between people (email, live discussions, etc.)

Communication between processes (such as between industrial

computers)

Guaranteeing full access to information for a specified group of

people (networked databases)

Multiplayer video games

Networks are also used for standardizing applications. The term

groupware is generally used to refer to tools that let multiple people work

over a network. For example, email and group scheduling can be used to

communicate more quickly and efficiently. Here's a glimpse of the

advantages that such systems have:

Lower costs, due to sharing data and peripherals,

Standardizing applications,

Providing timely access to data,

More efficient communication and organization.

Today, with the Internet, networks have become more unified. It is clear,

then, that there are several reasons to install a network, whether for a

business or an individual.

Similarities between types of networks

The different types of networks generally have the following points in

common:

Servers: computers which provided shared resources to users, by

means of a network server.

Clients: computers which access the shared resources provided by

a network server.

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Connection medium: how the computers are linked together.

Shared data: Files that can be accessed on the network servers

Printers and other shared peripherals: files, printers, or other

elements employed by the network's users

Miscellaneous resources: other resources provided by the server

Types of networks

There are usually said to be two types of networks:

Peer-to-peer networks

Networks organized around servers (Client/Server)

These two types of networks have different capabilities. Which type of

network to install depends on the following criteria:

Size of the business

Level of security required

Type of activity

Skills of the administrators available

Volume of traffic over the network

Needs of the network's users

Budget set aside for operating the network (not just purchasing it,

but also upkeep and maintenance)

A server is a computer that provides services to clients and controls access

to hardware, software and other resources. A client is a computer that

request services from a server computer

On a client/server network, one computer act as a server Client/Server that

provides services and the other computers (client) on the network request

services from the server. A server is a computer that controls access to the

hardware, software and other resources on the network and provides a

centralized storage area for program. A client is a computer that request

services from a server computer. Peer-to-peer is a simple, inexpensive

network that Peer-to-Peer typically connects fewer than 10 computers. All

computers in the network have equal capabilities to use the resources

(hardware, software, data and file) available on the network. With peer-to-

peer networks, there is no central server.

The Differences between Client/Server and Peer-to-Peer Client/Server

Peer-to-Peer

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Server has to control ability

All computers have equal while client‟s don‟t ability2) Higher

cabling cost

Cheaper cabling cost3) It is used in small and large

Normally used in small networks with less than 104) Easy to

manage computers5) Install software only in the

Hard to manage server while the clients share 5) Install software to

every the software computer6) One powerful computer

No server is needed acting as server

What is the Internet?

The Internet links are computer networks all over the world so that users

can share resources and communicate with each other. Some computers

have direct access to all the facilities on the Internet such as the

universities. And other computers, eg privately-owned ones, have indirect

links through a commercial service provider, who offers some or all of the

Internet facilities. In order to be connected to Internet, you must go

through service suppliers. Many options are offered with monthly rates.

Depending on the option chosen, access time may vary. The Internet is

what we call a meta network, that is, a network of networks that spans the

globe. It's impossible to give an exact count of the number of networks or

users that comprise the Internet, but it is easily in the thousands and

millions respectively. The Internet employs a set of standardized protocols

which allow for the sharing of resources among different kinds of

computers that communicate with each other on the network. These

standards, sometimes referred to as the Internet Protocol Suite, are the

rules that developers adhere to when creating new functions for the

Internet. The Internet is also what we call a distributed system; there are

no central archives. Technically, no one runs the Internet. Rather, the

Internet is made up of thousands of smaller networks. The Internet thrives

and develops as its many users find new ways to create, display and

retrieve the information that constitutes the Internet.

Introduction to the World Wide Web

The World Wide Web (also referred to as WWW or W3) is the fastest

growing area of the Internet. While gopher was an important step in

allowing users to "browse" through the Internet's vast resources, the World

Wide Web has raised excitement about the Internet to new heights.

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What makes the World Wide Web appealing and innovative is its use of

hypertext as a way of linking documents to each other. A highlighted word

or phrase in one document acts as a pointer to another document that

amplifies or relates to the first document. When looking at a WWW

document, the reader doesn't have to follow every pointer, or link (also

called a hypertext link), only those that look interesting or useful. In this

way, the user tailors the experience to suit his or her needs or interests.

The other very appealing aspect of the World Wide Web is the use of

graphics and sound capabilities. Documents on the WWW include text,

but they may also include still images, video, and audio for a very exciting

presentation. People who create WWW documents often include a

photograph of themselves along with detailed professional information and

personal interests. (This is often called a person's home page.)

What makes the WWW work?

WWW is another example of client/server computing. Each time a link is

followed, the client is requesting a document (or graphic or sound file)

from a server (also called a Web server) that's part of the World Wide Web

that "serves" up the document. The server uses a protocol called HTTP or

HyperText Transport Protocol. The standard for creating hypertext

documents for the WWW is HyperText Markup Language or HTML.

HTML essentially codes plain text documents so they can be viewed on

the Web.

Uniform Resource Locators or URLs:

A Uniform Resource Locator or URL is the address of a document you'll

find on the WWW. Your WWW browser interprets the information in the

URL in order to connect to the proper Internet server and to retrieve your

desired document. Each time you click on a hyperlink in a WWW

document, you're actually instructing your browser to find the URL that's

embedded within the hyperlink.

The elements in a URL: Protocol://server's address/filename

Hypertext protocol: http://www.aucegypt.edu

Gopher protocol: gopher://gopher.umm.tc.edu

File Transfer Protocol: ftp://ftp.dartmouth.edu

Telnet Protocol: telnet://pac.carl.org

News Protocol: news:alt.rock-n-roll.stones

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WWW Clients, or "Browsers":

The program you use to access the WWW is known as a browser because

it "browses" the WWW and requests these hypertext documents. Browsers

can be graphical, like Netscape and Mosaic, allowing you to see and hear

the graphics and audio; text-only browsers (i.e., those with no sound or

graphics capability) are also available. All of these programs

understand http and other Internet protocols such as FTP, gopher, mail,

and news, making the WWW a kind of "one stop shopping" for Internet

users.

Network Devices and the Internet of Things

All kinds of ordinary household gadgets can be modified to work in an IoT

system. Wi-Fi network adapters, motion sensors, cameras, microphones

and other instrumentation can be embedded in these devices to enable

them for work in the Internet of Things. Home automation systems already

implement primitive versions of this concept for things like light bulbs,

plus other devices like wireless scales and wireless blood pressure

monitors that each represents early examples of IoT gadgets. Wearable

computing devices like watches and glasses are also envisioned to be key

components in future IoT systems.

The same wireless communication protocols like Wi-Fi and Bluetooth

naturally extend to the Internet of Things also.

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