Burp Suite is a framework of web application pentesting tools. See ZAP for a similar (completely free) tool).
Burp Suite needs to be able to act as a proxy. Follow this tutorial by tryhackme to set up FoxyProxy in firefox
Burp suite has a number of different components:
From the Positions tab, you may select different fields to attack.
Attack type
Add payloads (dictionaries).
To start the attack, press the attack button in the top right corner. :)
The intercept tab intercepts web traffic and allows you to view the request. You can send particular parts of this request to different modules, such as the Intruder module.