It is called burn card to a form of card games, in which cards are dealt at different times of the game, and so before returning to distribute or show on the table a new card (or batch of cards ) the first of the cards that should have been dealt is "rejected" or "burned".
Discarding it is left in the discard pile and the dealer ("Dealer") or croupier must prevent anyone from seeing that discarded card. Hence, it is called burn ("burn").
The purpose of this procedure is to prevent anyone from observing any mark made on any previous hand on the deck of cards left on the table until new cards are dealt or discovered.
For example, in the Texas Hold'em poker mode, one card is "burned" before the Flop, another before the Turn and another before the River.
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