2. Client side processing

When you visit a web site, you usually use a browser program such as Edge, or Chrome, or Firefox.

The browser sends a request to the web server for the code that make up the page you want to view. Since the browser is making the request in this case, it is the 'client'.

The browser then interprets the markup language and code it receives back, and renders the page for you to see. Different pages use different web technologies (which we discuss in this section here).

Rendered pages may then allow further requests from the client. These requests are validated to ensure that they are formatted correctly. You can read more about entry validation in our GCSE section here.

Client side processing means that the web page gets the client - your computer - to do the validation and other processing itself, rather than the server.

There are several common languages for this kind of processing code. The one you will need to know about is JavaScript. We have a page etailing javascript here.

Client side processing is also used to create interaction 'widgets' to help the user provide the correct information. For example, click into the input box below and (if your school allows JavaScript to run on your browser) you should see a calendar widget appear.

The entire calendar widget is created by a piece of JavaScript code included in this page. It tells your browser to process any inputs you make. This is client side processing.