BTEC NationalBTEC National

Level 3Level 3

Website Production Website Production

Lesson objectivesLesson objectives

To understand factors that influence To understand factors that influence website performancewebsite performance

To understand the risks to the To understand the risks to the security of a websitesecurity of a website

StarterStarter

AptimizeAptimize

Improves website performanceImproves website performance

Think about the things that are Think about the things that are downloaded when you visit the pagedownloaded when you visit the page

http://www.youtube.com/watch?http://www.youtube.com/watch?v=JTwges72rdgv=JTwges72rdg

CompressionCompression We discussed compression is used in images, We discussed compression is used in images,

such as bitmap (resolution dependent) and such as bitmap (resolution dependent) and vectorvector

Compress images = lose qualityCompress images = lose quality

We compress images because it will reduce We compress images because it will reduce the file sizethe file size

Reduce file size = smaller page = faster Reduce file size = smaller page = faster download especially for those on dial-updownload especially for those on dial-up

ExampleExample

GIF: 64KB JPEG: 24KB

Activity images and video(15)Activity images and video(15)

Activity: look at an existing website. Open Activity: look at an existing website. Open the code for that website: view >> page the code for that website: view >> page source. What image file types have been source. What image file types have been used and why?used and why?

Find examples of different software you can Find examples of different software you can use to compress imagesuse to compress images

1. download an image1. download an image 2. Use: imageoptimizer.net, 2. Use: imageoptimizer.net,

shrinkpictures.com or jpeg-optimizer.com to shrinkpictures.com or jpeg-optimizer.com to check what the image will look like when check what the image will look like when compressed compressed

Activity sound and video (12)Activity sound and video (12)

Apart from images we can also Apart from images we can also compress sound files:compress sound files:

WAV = uncompressedWAV = uncompressed MP3 = compressed formatMP3 = compressed format

Videos can slow down a website, a Videos can slow down a website, a possible solution is streaming. Explain possible solution is streaming. Explain how… how…

Server side factor (12)Server side factor (12) If a website is slow to download what do If a website is slow to download what do

you think will happen to the visitors you think will happen to the visitors Bandwidth: determines how much Bandwidth: determines how much

traffic can be handled by the server, at traffic can be handled by the server, at any one timeany one time

Find out how the performance of a Find out how the performance of a server can affect the usersserver can affect the users

Look at bandwidth, server memory, Look at bandwidth, server memory, processing and storageprocessing and storage

Find out the Internet connection speedFind out the Internet connection speed

2.3 Security2.3 Security There are many risks to the security of a There are many risks to the security of a

websitewebsite

An example of this is hackers who attempt to An example of this is hackers who attempt to access a computer system to steal data , access a computer system to steal data , change it or destroy itchange it or destroy it

Viruses and general malware cause damageViruses and general malware cause damage

http://www.youtube.com/watch?http://www.youtube.com/watch?v=IUVPxcaEA8w v=IUVPxcaEA8w

Security protection mechanismsSecurity protection mechanisms

FirewallFirewall

SSLSSL

Adhere to standardsAdhere to standards

Activity: securityActivity: security

Research the threats to websites Research the threats to websites including hackers and viruses. Make including hackers and viruses. Make notes for future reference in your notes for future reference in your courseworkcoursework

Research the methods to protect Research the methods to protect websites including firewalls. websites including firewalls.

Server side factor (12)Server side factor (12) If a website is slow to download what do If a website is slow to download what do

you think will happen to the visitors you think will happen to the visitors Bandwidth: determines how much Bandwidth: determines how much

traffic can be handled by the server, at traffic can be handled by the server, at any one timeany one time

Find out how the performance of a Find out how the performance of a server can affect the usersserver can affect the users

Look at bandwidth, server memory, Look at bandwidth, server memory, processing and storageprocessing and storage

Rest of the lessonRest of the lesson

Work on P1 criteria challenge 1Work on P1 criteria challenge 1

Work on P2 criteria challenge 2Work on P2 criteria challenge 2