The git bisect start command initializes a binary search to find the commit that introduced a bug or regression. It allows you to mark commit ranges as good or bad, helping git narrow down the faulty commit. This command is useful when you have a large number of commits and want to pinpoint the cause of a problem.
After the bisect operation has started further commands need to be issued such as git bisect bad to mark a commit as bad, git bisect good to mark a commit as good, and git bisect skip to skip a commit during the search. Lastly, git bisect reset ends the bisect session and returns the HEAD to where it was before the bisect operation started.