Google Classroom enables teachers to distribute assignments, have students complete/submit those assignments, and give feedback. This is all via the Google Drive platform as a way to distribute and collect assignments without all the former hassles of setting up files, sharing files, making sure students copy these files, making sure permissions are correct, making sure students share files to you, etc. etc.
These hassles are now gone! You can use the revisable, editable docs via Google Drive with much more ease.