Wfuzz has been created to facilitate the task in web applications assessments
and it is based on a simple concept: it replaces any reference to the FUZZ
keyword by the value of a given payload.

A payload in Wfuzz is a source of data.

This simple concept allows any input to be injected in any field of an HTTP
request, allowing to perform complex web security attacks in different web
application components such as: parameters, authentication, forms,
directories/files, headers, etc.

Wfuzz is more than a web content scanner:

* Wfuzz could help you to secure your web applications by finding and
exploiting web application vulnerabilities. Wfuzz’s web application
vulnerability scanner is supported by plugins.

* Wfuzz is a completely modular framework and makes it easy for even the newest
of Python developers to contribute. Building plugins is simple and takes
little more than a few minutes.

* Wfuzz exposes a simple language interface to the previous HTTP
requests/responses performed using Wfuzz or other tools, such as Burp. This
allows you to perform manual and semi-automatic tests with full context and
understanding of your actions, without relying on a web application scanner
underlying implementation.

It was created to facilitate the task in web applications assessments, it's a
tool by pentesters for pentesters ;)