Registrants are the individuals and organizations who actively participate in your event. Registrants are the event's players, team captains, coordinators, instructors, vendors and other businesses that supply a service or product for the event, or any other person who pays to attend. Registrants can be constituent or nonconstituent. Registrant participant records can be linked to constituent records to update the events tab of the constituent record. 


Guests are individuals or organizations who attend the event as invitees of a registrant. Add guests on the Participants tab of the event record or on the General 1 tab of a registrant's record. A guest can be a constituent or nonconstituent, however the guest record can only be linked to a constituent record. 

For more information on adding guests, review: 


Sponsors are individuals or organizations sponsoring, or representing, an individual registrant or a group of registrants. Sponsors may pay all the registration fees, and the registrants may participate in the event as a group. You add sponsors from the event record's Participants tab. The sponsored registrants should have the organization's name in the Sponsored by field on the General 1 tab of the individual registrant record. 
For more information on adding sponsors to individual registrants, review: 
BB129332 - How to link a sponsor to a participant

For more information on participants, review: