Git commits are composed of all of the files in the commit, it’s parent and the commit message. This is an important guarantee that each checkout is valid without the rest of the repo. This allows you to have a lot of exotic implementations guarantee consistency between them. Meaning if your GitHub you can distribute commits across many servers. Or your Microsoft and you build partial checkouts for Gvfs. It’s what allows Git LFS to keep many of git’s core guarantees while making tradeoffs to improve areas where git is traditionally weak.