This document discusses the definition and purpose of invitations. It defines an invitation as a spoken or written request for someone to attend an event or activity. Invitations can be formal, originating from institutions or companies, or informal between friends and family. The structure of an invitation includes the invitee, details of the occasion such as date, time, and place. Examples are given of different types of events that use invitations such as parties, meetings, celebrations and more. The document concludes with sample questions about the details of an invitation.