Invitation Cards are displayed in emails containing calendar attachments.

This cards contains basic details of the event including title, time, location, recurrence Information, and reply option to send to the event organizer.

Upon receiving the invite, you can do the following actions.
Icons Definition
Accept Accept your invites.
Maybe or Decline If you have conflicting events, tap and propose a new time while replying to the event organizer.
Perform necessary actions on the invite.
Shows the event date and time details.
Shows the event location.
Shows the number of attendees.
Shows your availability status for the event by displaying Free or Busy.
Reply to send an attendance status to the event organizer.