The software uses the terminology registrant when referring to the person or organization that purchases the tickets. The registrant's name is shown in the Last Name/Constituent field on the Event and Event Attendance grid. The attendees are those people who are actually attending the event. On the Event grid > Details View and the Event Attendance grid, the attendees are listed under the Actual Attendee column. 

If the registrant does not provide the names of their guests (attendees) the registrant's name will be used as a placeholder until the actual attendees' names are updating on the Event Attendance grid using the Tools menu.

In the example below, Andrews Abbott Real Estate is the constituent that purchased the tickets. That constituent is the registrant. Their guest names, Julie Abbott, Bob Abbott, Geoff Bailey, and Gabrielle Clark are the attendees.

Franken Account Service is shown as both the registrant and actual attendee because that constituent purchased the tickets, but did not provide the names of the actual attendees at the time of purchase.

Bonnie Hadlock also purchased two tickets and she is shown as the registrant and well as one of the attendees along with her guest, Kasper Sage.