> Encoding and Transformations are techniques that change how data is represented or transferred without altering its core meaning. Common examples include URL encoding, Base64, HTML entity encoding, and Unicode transformations. Attackers use these methods as gadgets to bypass input filters, evade web application firewalls, or break out of sanitization routines.
Source: Encoding Transformations/README.md in PayloadsAllTheThings. From PayloadsAllTheThings by Swissky and contributors. MIT License, Copyright (c) 2019 Swissky.