During the earlier parts of this book, specifically in Chapter 5, Passive Information Gathering, and Chapter 6, Active Information Gathering, we discussed the importance of performing extensive reconnaissance on a target, whether it's a single system, network, or even a website. Each penetration test has a set of guidelines and stages. As you may recall, the following are the stages of penetration testing:

1. Reconnaissance (information gathering)
2. Scanning (and enumeration)
3. Exploitation (gaining access)
4. Maintaining access
5. Covering tracks

Gathering as much information as possible about a target helps us to determine whether the target has any security vulnerabilities and whether it's possible to exploit them. In the following section, we will begin by learning how to discover technologies that are being used on a website.