[_ikke_]

What you are missing is the difference between gits object model (with loose objects) and packfiles. The delta compression happens when you run `git gc` (git does this automatically as well on occasion), and packfiles is how git fetches and pushes history.

But when you create a new commit, that commit object is stored as a loose object, with any new file blobs and tree objects. This represents a complete snapshot of your working tree.

But git does not need to make a complete copy of the working tree on each commit. Because objects are referred to by the hash of their contents (with a git specific header), git only needs to store each version of a file once.

[Bjartr]

Everyone here is arguing past each other because one side defines "what git does" as the literal implementation details of git, and the other side defines "what git does" as the model it presents to the end user. I suspect the reason for this disconnect is partly due to the emphasis on understanding the "internals" of git and the fact that this is about between the internal implementation as it exists in code and the internal model/interface.