Conventional Commits are a convention on how to write git commit messages.
The aim is to make commit messages machine readable and use them with tools for automated sem-versioning, change logs and more.
There are even tools for linting messages in order to check if developers follow the rules of conventional commits (https://commitlint.js.org/).
Should we use it? I was personally very interested and a advocate for using them but...
after reading the following blog post i'm now not so sure anymore.
tl;dr commit messages are there for developers and not for users. This does not help with writing good commit messages that describe the WHY a change was made.