To see changes made to your files in Drive and keep track of who made those changes, you will want to view the past activity log in Google Drive. 

The past activity log can show you when someone:

• Edits or comments in Google Docs
• Renames a file or folder
• Moves or removes a file or folder
• Uploads a new file to a folder
• Shares or unshares an item

Accessing the activity logs

To learn how to view the activity log, visit Google's Support article View activity & file versions.