Git is the version control system that has eclipsed every alternative since 2010. Linus Torvalds wrote it in 2005 to manage Linux kernel patches; the model — content-addressable storage, commits as DAG nodes, branches as cheap pointers — turned out to scale from one-person scripts to projects with tens of thousands of contributors.
Day-to-day Git for most engineers is a small subset: branch, commit, push, pull, rebase, merge. The interesting skills are the recovery ones — interactive rebase, reflog, cherry-pick, bisect — and understanding what the commands actually do under the hood when something goes wrong. The internals course (Git from the bottom up) is short and changes how you read every command after.
