(
Automatic 
Teller 
Machine machine)  A banking terminal that accepts deposits and dispenses cash.  ATMs are activated by inserting a cash or credit card that contains the user's account number and PIN on a magnetic stripe.  The ATM calls up the bank's computers to verify the balance, dispenses the cash and then transmits a completed transaction notice.  The word "machine" in "ATM machine" is redundant but widely used.  See 
Bitcoin ATM and 
cashless ATM.
The Money Machine
Rubber rollers move one bill at a time from the currency box (each holds about 2,000 bills) to the dispenser area.  A sensor determines if two or more bills are stuck together or if the wrong denomination was pulled and causes them to be inserted into the reject box.