Event Categories can be created to allow for flexibility in filtering events on the Calendar, or via the the Event module.
Categories can be created by going to the Events > Administration > Categories. From here you will be able to create as many Categories as required
Once you have created Categories, you are able to add these to Events or Event Templates when creating or editing from the Categories dropdown.
You are then able to filter Event Categories via the Schedule, Past Events, or Upcoming Events tabs, or via the Calendar module.