Git add / rm (commit)

So, I took a website, some of which were running git (one of the developers used it, and the other did not). So I'm going to dedicate everything so far and work from there.

However, there are several files with git status, which I do not quite understand. They are designated as:

# Changed but not updated:
#   (use "git add/rm <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)

So, if I just run git commit, will there be changes to these files in the repository? It's just that I don’t understand why you would add / rm - it seems to be adding and then removing everything in one fell swoop.

Thank you for your help!