The Programs all use the same data file for your Accountant 9which was spun off of Premier Editions), and Pro. Enterprise all use their own file design.
For the issue of Changes, you are working in a File. Whose file is this? Your copy of their file as a qbw (your working file), the Accountants Copy file(a specific divided file they sent you as .qbx, you work in it converted to .qba,you Export the Changes file as .qby, and they Import your changes file, releasing their Restriction seen in their title bar). Or, you got a .qbb file and they stop working until you make updates and give them back an updated .qbb (backup) file, which they will use for Restore and that replaces their copy of their file.
The QB program is like Word. The Data files are like letters. Whose Letter are you working int, and are you sending back that Letter entirely, or just informing them of your edits? See how this is a Parallel to what you asked?