Git bisect is a git command that makes it easier to track down where a problem was introduced to a codebase.
In large projects you may find that a change was added to the code that causes a problem and you then need to track down where that problem occurred. Knowing where the problem was introduced makes debugging the issue a lot easier.
You could just checkout commits until you find the culprit, but git comes with the bisect tool that can assist in this process and can even be automated to quickly find the problem.
Read more here: https://www.hashbangcode.com/article/getting-started-git-bisect