Google Drive is great for collaborative group projects because everyone can share the same set of files and work in unison. But that can make it hard to track the changes to all your shared documents, spreadsheets, presentations and so on. There’s a tool in Google Drive to help you out.
From the main Drive interface you can click the ⓘ button in the top right corner to display the activity stream. This shows you who has taken any sort of action on the files and folders in your Google Drive.
Any activity such as editing and commenting on notes, adding a new document, renaming a spreadsheet or similar will prompt and entry in the Activity Stream.
If you want to see the activities for just a selection of your files and folders, select them by checking their checkboxes in the main list; the activity stream will change automatically to show activity on just the items you’ve selected.