You’ll notice a new "activity" stream in your New School Drive App. When you open Drive, click the “Details and activity” button (ⓘ) on the top right corner and an activity stream will appear, showing you who has taken action on files and folders in My Drive. You’ll see an outline of what your peers and colleagues have been doing, such as editing and commenting on notes, adding a new spreadsheet, renaming a presentation, etc. If you select a specific file or folder, the stream will change to show you specific information about that item.
For more information about this new feature see Google's activity stream support information available online.