Determining entities within your collections enables them to be tagged and connected to other items, more easily bringing them together.
An entity for ‘person’ might include a database of surgeons or musicians, for example. For ‘place’ it might be hospitals or venues. For ‘thing’ it might be surgical or even musical instruments.
Each entity will have its own attribute set: all of the things that make up the unique qualities of that entity. So for ‘person’ it might be first name, last name, date of birth or occupation. Together with attributes, attribute sets, and entities, your database will be totally connected, taking full advantage of cross-collection searching.