WEEK 4: Concept of client server, Cascading style sheet (CSS), and Java Script.

During week 4 we learn 3 chapter which is concept of client server, Cascading style sheet (CSS), and Java Script.

1.0 concept of client server

Clients and server corporate to deliver network service.
clients : initiates communication
server : send information back to clients

Client-Server Relationships

Fundamental paradigm that determines the characteristics of computer languages on the web. 

The difference

1. How the language are invoked

• Server side

invoked by submit button and typing in a URL.

• Client side

HTML code.

2. What resources and information they can access

• Server side

Operate as normal user program unless web administrators imposed restriction.

• Client side

They have full access to the structures and operation of the browsers.

3. What structures can be manipulated

• Server side

can manipulate any resources on the server that are accessible to any user program.

• Client side

cannot manipulate anything on the server

4. How they interact with user and system.

• Server side

Cannot manipulate any information on the client browser, cannot modify the existing.

• Client side

interact easily with user

5. The speed and predictability of their interactions

• Server side

modern traffic

• Client side

swift, immediate and predictable

How client side and server side script works

Client Side Script

• Interpreted or executed by the browser/client
• Run on the user's workstation
• Example: JavaScript, JScript, VBScript

Server Side Script

• Interpreted or executed by the web server
• Provide interaction web sites that interface to database or data stores
• example: php, asp, netbean

2.0 Cascading Style Sheet (CSS)

Cascading style sheet is a clients side

WHY CSS?

• Allows much richer document appearances that HTML
• Reduce workload by centralizing commands .
• Use same style on multiple page
• Reduce page download size
• can use HTML for content but use CSS for presentation

3.0 JavaScript

Client side scripts

Common uses of javascripts include: alerts message, popup windows, dropdown menu, form validation and displaying date and time

What do i need to create javascript

Can create using the same equipment as HTML

• Computer
• text editor: notepad etc
• web browser: Internet explorer etc