In this PHP programming exercise we take a look at PHP and HTML, What is the Back-End, Web Server, Database, and Application Servers in PHP Explained. This lesson is based on Codecademy’s Learn PHP course. We are in the section, “PHP and HTML”, and this lesson is, “What is the Back-End”. In it, we learn that the “back-ends” of websites will differ from each other depending on a site’s needs. Typically, a website will have the following pieces. We have a web server, an application server, and a database. The web server is a computer that will listen to a request that a client, one of which is a browser, will send it. The server will send back responses. The application server is usually a collection of our programming logic that will deliver dynamic content to a browser, or client. An application server will handle tasks such as site security and interactions with data. The database stores important information like usernames and passwords. Learning about how back-ends work is key to becoming a good PHP developer. Practice understanding the back end and how it is different from a site’s front end. Thanks for watching PHP and HTML, What are the Back-End, Web Server, Database, and Application Servers in PHP Explained.