essentials of it lecture no 2

8/8/2019 Essentials of IT Lecture No 2

1/14

1 2010

Essentials of IT

Course : - BBA

First Year


2/14

Enterprise Planning Systems 2 2007

an electronic machine, operating under the control of instructions stored in

its own memory, that can accept data (input), manipulate the data accordingto specified rules (process), produce results (output) and store the result for

future use.

Data a collection of unorganized facts, which can include words, numbers,

images and sounds.

Computers manipulate and process data to create information.

Information data that is organized, has meaning and is useful. Example;

report, newsletter, receipt, picture, invoice, check.

Input data entered into computer.

Output the processed results.

What is a Computer


3/14


Storage an area to hold data and information for future use.

Information processing cycle the cycle of input, process, output andstorage.

User

a person that communicates with a computer or uses the information itgenerates.

Hardware the electric, electronic and mechanical equipment that makes up acomputer.

Software the series of instruction that tells the hardware how to performtasks.

Hardware needs the instructions provided by software to process data intoinformation.

Continued


4/14


Characteristics of Computers

Speed the speed with which computers perform is way beyond humancapabilities.

Accuracy Consistently high , errors occur, but these are almost always dueto human error rather then technological weakness

Diligence

Unlike human beings computer does not suffer from limitationsassociated with human beings like tiredness or lack of concentration

Versatility Computers are capable of performing any task, provided the taskcan be reduced to a series of logical steps

Intelligence It performs only those tasks that can be broken down into seriesof steps

Storage Computers can store & recall any amount of information throughdifferent storage capability & thus information can therefore be retained as longas desired and recalled as and when required


5/14


Components of Computers

A computer consist of a variety of hardware components that work togetherwith software perform calculation, organize data, communication with

other computers.

Hardware components include:-

Input deviceOutput device

System unit

Storage device

Communication device


6/14


Input Device

Allows a user to enter data and commands into the memory of a computer.

Three commonly used input devices are the keyboard, the mouse and a

microphone.

Computer keyboard contains keys that allow user to type letters of the

alphabet, numbers, spaces, punctuation marks and other symbols.

Mouse a small handheld device that contains at least one button.

Microphone allow user to speak to the computer in order to enter data

and control the actions of the computer.


7/14


Output Device

Used to convey information generated by a computer to the user.

Three commonly used output devices are printer, monitor, and speaker.

Printer produces text and graphics such as photographs, on paper or

other hardcopy medium.

Monitor used to display text and graphics.

Speaker used to hear music, voice and other sound generated by the

computer.


8/14


System Unit

Is a box-like case made from metal or plastic that houses the computer circuitry.

Contains:-

Central Processing Unit (CPU) - interprets and carries out the

instructions that operate a computer, including computations.

Memory - a series of electronic elements that temporarily holds data and

instructions while the CPU is processing them.

CPU and memory are chips; electronic device that contains many

microscopic pathways designed to carry electrical current.


9/14


Storage Device

A mechanisms used to record and retrieve data, information, and instructions toand from a storage medium.

As a source of input transfer item from storage into memory.

Common storage devices are floppy disk drive, hard disk drive, CD-ROM drive,

and DVD-ROM drive.


10/14


Communication Device

Enable a computer to exchange items such as data, instructions, andinformation with another computer.

It transmit these items over transmission media such as cables or telephone

line, used to established a connection between two computers.

Modem; enable computer to communicate via telephone line.


11/14


Software

Also called a computer program/program; a series of instructions that tells thehardware of a computer what to do.

Software can be categorized into two types:

1. System Software - controls the operation of the computer and its

devices and serves as the interface between a user and the

computers hardware. Two types of system software; Operating system - contains instructions that coordinate the

activities of hardware devices.

Utility programs - perform specific tasks usually related to

managing a computer, its device or its programs.


12/14


Software Contd..

2. Application Software - performs specific tasks for users, such ascreating documents, spreadsheets, databases, or presentation

graphics.

Word processing software create documents (eg. Letter, memo)

Spreadsheet calculate number arranged in rows and columns.

Often used for budgeting, forecasting, and other financial task.

Database store data in organized fashion, retrieve, manipulateand display data in meaningful form.

Presentation graphic create documents called slides for

presentation.

Other software application reference, education and

entertainment; desktop publishing; photo and video editing;multimedia authoring; network, communication, electronic mail and

web browser; accounting.


13/14


Application software is available as packaged software, custom software,shareware, freeware and public-domain software.

Packaged Software:-

Is designed to meet the needs of a wide variety of users, not just a single

user or company.

Also called commercial off-the-shelf software.

Custom Software:-

Sometimes a user or organization cannot find packaged software that

meets all of its needs.

In this case, they can use custom software a program or programsdeveloped at a users request to perform specific function.

Software Contd..


14/14

14 2010

End of Presentation

essentials of it lecture no 2

Documents