The Request-Response Cycle of a Web Application

To understand how an application loads in a browser, or how it gets data from a server, it is important to know about the Request-Response cycle. The Request-Response model is used extensively and it's not only applicable to web applications (such as using a browser). In fact, it's also used in the communication between machines; for example, for fetching data from a database, which involves the application system on one side and the database system on the other side. In this case, the application is the client for the database system.

HTTP is the most commonly used protocol for web applications and, since it could take up a whole book itself, we'll cover only the most important part here, explaining how it works.

Each web application takes a request and prepares a response for it. Usually, the Request-Response cycle for a web application looks similar to this:

1. The client makes a request; for example, GET...