A slot machine (American English), poker machine (Australian English), or fruit machine (British English) is a certain type of casino game. Classically, a slot machine is a coin-operated machine with three or more reels that rotate when a lever on the side of the machine is pulled. The machines include a currency detector that validates the coin or money inserted to play. (The slot machine is also known informally as a one-armed bandit because of its appearance.) The machine typically pays off based on patterns of symbols visible on the front of the machine when it stops. Modern computer technology has resulted in many variations on the slot machine concept. Today, slot machines have become one of the most popular attractions in casinos.