This is the description that shows in the Timeline Files list when users view the list of available timelines. This description should be fairly brief as only about 80 characters are displayed in the list. It should include the region that the timeline covers and the type of events. Often, the description is the same as the timeline file name. For example, Rulers of England, Russian Wars in the 1800s, The Plagues of Europe, etc.
The Timeline Files list is reached by choosing Timeline Files from the View tab of the Ribbon bar.