A croupier or dealer is someone appointed at a gambling table to assist in the conduct of the game, especially in the distribution of bets and payouts. Croupiers are typically employed by casinos. Training methods to become a casino croupier vary from country to country. In North America, blackjack is almost always the game that dealers learn first, as it is simple and popular, and when the dealer makes errors, they tend not to cost the casino much money. In Europe, croupiers tend to learn roulette first. Complex, busy games such as craps, with complicated payout systems, etc., are usually reserved for the most competent and/or ambitious dealers.

Source: Wikipedia