My latest Git commit hash was:
5ba786fcc93e8092831c01e71444b9baa2228a4f
You may have noticed that even though we (you and I) both have the same content in our repositories, we have different commit hashes. While commit hashes are derived from their content changes, there's also some other stuff that affects the end hash. For example:
All this to say that hashes are effectively unique in practice. While SHA-1 collisions are possible under contrived conditions, you won't accidentally create two different commits with the same hash, and because they're generated automatically for you, you don't need to worry too much about what goes into them right now.
Git uses a cryptographic hash function called SHA-1 to generate commit hashes. We won't go into the details of how SHA-1 works in this course, but it's important to know because you might also hear commit hashes referred to as "SHAs".