WebScripting

WebScripting is the process of creating and embedding scripts in a web page.

A script is a list of commands embedded in a web page. Scripts are interpreted and executed by a certain program or scripting engine.

Scripts may be written for a variety of purposes such as for automating processes on a local computer or to generate web pages on the web.

The programming languages in which scripts are written are called as scripting language such as VBScript, JavaScript, ASP, PHP, Perl, JSP etc.

Types of Scripts

There are two types of scripts:

Client-side scripting enables interaction within a web page.

The client-side scripts are downloaded at the client-end and then interpreted and executed by the browser.

The client-side scripting is browser-dependent. That is, the client-side browser must be scripting enabled in order to run scripts.

Client-side scripting is used when the client-side interaction is used.

Uses of client-side scripting may be:

to get data from the user's screen or browser
online games
customising the display of page in browser without reloading the page, e.g., rollover a hyperlink highlights that link without reloading the page

Some popular client-side scripting languages are, VBScript, JavaScript, PHP

Server-side scripting enables the completion or carrying out a task at the server-end and then sending the result to the client-end.

In server-side script, the server does all the work, so it does not matter which browser is being used at client-end.

Server-side scripting is used when the information is sent to a server to be processed at the server-end.

Uses of server-side scripting may be:

password protection
browser customization or sending information as per the requirement of client-end browser
form processing
building and displaying pages created from a data base
dynamically editing changing or adding content to a web page

Some popular server-side scripting languages are, PHP, Perl, ASP, JSP, etc.

The table given here compares or tells the differences between the client-side and the server-side scripts:

Client-Side Scripting	Server-Side Scripting
Script code is downloaded and executed at client end	The script is executed at the server-end and the result is sent to the client-end
Response to interaction is more immediate once the program code has been downloaded	Complex process are more efficient as the program and associated resources are not downloaded to the browser
Services are secure as they do not have access to files and databases	Have access to files and data bases but have security considerations when sending sensitive information
Browser dependent	Does not depend on browsers
Affected by the processing speed of user's computer	Affected by the processing speed of the host server