Making changes to filed already pushed into git

If I want to make changes to and re-submit filed already pushed into git, do I have to re-commit with a different description (git commit -m ‘description’) or do I use the same one as before (e.g. complete 02_calculator)

If you want to make any changes to files pushed up to git, you have to make a new commit, and then push that commit/those changes up separately. You can push commits up to github to add files, and you can also push commits up to github to edit files. You don’t have to do anything special to edit a file that’s already there; git takes care of that for you!