Those playing Pineapple Hold’em are dealt three cards instead of the standard two hole cards. The rub here is that the player must discard one of these three cards at some point.
In the traditional game of pineapple hold’em (it’s not a very long tradition) you discard after the first round of betting, but before the flop. Some folks play a variation of this game called “Crazy Pineapple” where the discard happens after the flop.