Using TheHarvester is a relatively simple and straightforward process. In order to make the most of the program, we have to understand the program’s options, or “flags”, used in each execution. This is a terminal-based program, so understanding its flags is crucial to its operation. Additionally, in order to properly use these flags, we must understand the types of data that penetration testers are looking for.Reconaissance takes place at the beginning of a penetration testing operation. This stage involves gathering as much useful information as possible for penetrating the target’s network and devices. Email addresses, domain names, server addresses, organizational member names, open ports, and user names are all targeted points of information. Using this data, we can build specialized spearphishing emails, gain network access through unsecured ports, and find login menus for brute-forcing and password cracking.