The History tab on the Dashboard shows your student's play history. History items are created every time your student passes, fails, or skips an activity, and whenever a milestone or subject is passed. These events are sorted by subject, and you can filter by date or event type. You may sort the events by any column by clicking on that column's header.
In each event, you may use the Try button to try the given activity in Parent Mode to get a better understanding of what your student was working on. This allows you to play that activity without affecting your student's progress.