RSVP is an abbreviation of the French phrase "répondez sil vous plaît," which translates to "respond, if you please". It is a request for the invited guests to indicate whether they will be able to attend an event. RSVPs are used to learn how many people are going to attend an event, which is helpful for the host to determine how much space, food, and budget they need to make their event happen. Invitations requiring an RSVP will have instructions on how to respond, which can be a simple text, a card you mail back to the host, or an electronic RSVP request. It is best to respond as soon as possible rather than delay, and if you are not sure you can attend, reach out and tell the event organizer.