Afikoman Cover

Afikoman (meaning "that which comes after" or "dessert") is a half-piece of matzo which is broken in the early stages of the Passover Seder and set aside to be eaten as a dessert after the meal. Based on the Mishnah in Pesahim 119a, the afikoman is a substitute for the Korban Pesach, which was the last thing eaten at the Passover Seder during the eras of the First and Second Temples and during the period of the Mishkan. The Gemara states that it is forbidden to eat any other food after eating the afikoman, in order to keep the taste of matzo in our mouths.
In some families, the head of the household hides the afikoman for the children to find, and rewards them with money or candy. In other families, the children "steal" the afikoman and ask for a reward for its return. Either way, the afikoman has become a device for keeping children awake and alert during the Seder proceedings, until the time it is needed for dessert.