Yeah, you're right, technically it's not a "diff", it's the changed files.
I don't think this technical detail has any consequences for the general mental model of Git though - as evidenced by the fact that I have been using Git for years without knowing this detail, and without any problems.
It's all the files. Content-addreasable storage means that they might not take up any more space. Smart checkout means they might not require disk operations. But it's the whole tree.
Yeah, you're right, technically it's not a "diff", it's the changed files.
I don't think this technical detail has any consequences for the general mental model of Git though - as evidenced by the fact that I have been using Git for years without knowing this detail, and without any problems.
It's all the files. Content-addreasable storage means that they might not take up any more space. Smart checkout means they might not require disk operations. But it's the whole tree.