A Cherry is a special item found in Super Mario Bros. 2. When Mario, Luigi, Peach, or Toad collected five Cherries, an invincibility-granting Starman would float upwards from the ground. Cherries appeared quite a bit in this game, and many of them could be found in every level. They also appeared in the slot machines of the same game, and when a player lined up even one of them, he or she would get points. They would reappear as icons in Super Mario World 2: Yoshi's Island's slot mini-game.
A Cherry-shaped cloud can be seen in the background of Cloudy Climb in Paper Mario, and Cherries later appeared in the background of Super Smash Bros. Melee's Mushroom Kingdom 2 (a.k.a Subcon) stage. However, they were just for scenery and played no role in gameplay.
Cherries are meant to be thrown in the 4-player or duel Mario Party DS Minigame Cherry Go Round where the person to throw their cherry the furthest is the winner of the event.