The back-ends of websites will differ depending on the needs of the site. Typically, they’ll have at least the following components:
- A web server: a web server is a computer or program which listens for requests from clients and sends back responses. This component is well suited to handling delivery of static content.
- An application server: this is actually often a collection of programming logic which is needed to deliver dynamic content to a client. The application server will often handle other tasks such as site security and interacting with data.
- A data base: important information like usernames and passwords has to be stored and accessed somewhere. A large web application will often have multiple databases to store all different types of data needed to run the site smoothly.
PHP can be used in many capacities in the back-end. However, in this lesson, we’ll get started small by focussing on one small role the PHP application server can play in generating HTML which the web server will send to a client.
When you are ready, move on to the next exercise.