Web applications involve much more than just HTML code and web servers. If you are not a programmer who is actively involved in the development of web applications, then chances are that you are unfamiliar with the inner workings of the HTTP protocol, the different ways web applications interact with the database, and what exactly happens when a user clicks a link or enters the URL of a website into their web browser.

As a penetration tester, understanding how the information flows from the client to the server and database and then back to the client is very important. This section will include information that will help an individual who has no prior knowledge of web application penetration testing to make use of the tools provided in Kali Linux to conduct an end-to-end web penetration test. You will get a broad overview of the following:

• HTTP protocol
• Headers in HTTP
• Session tracking using cookies
• HTML
• Architecture of web applications