What is a modification?

We need to keep in mind that a version is never anything more than a set of code modifications that we want to freeze because it corresponds to an interesting (more advanced) state compared to the previous version.

For Git, each file is simply a set of lines, and is treated as such. It is specialized for handling text (in this case, code), so it is "smart" enough to help us version our code, but it cannot guess the logic behind the modifications each developer makes.