RSVP stands for a French phrase, "répondez, s'il vous plaît," which means "please reply." The person sending the invitation would like you to tell him or her whether you accept or decline the invitation. Etiquette rules followed in most Western cultures require that if you receive a formal, written invitation, you should reply promptly, perhaps that same day.
For hosts who are planning a dinner party, a wedding or a reception, this is important from a practical point of view, because they need to know how many people to count on and how much food and drink to buy.
More important, though, is the simple courtesy of responding to someone who was nice enough to invite you, even if it is to say that you regret that you will not be able to attend.
Anyway nice Team Work
