automated teller machine

automated teller machine (ATM), device used by bank customers to process account transactions. Typically, a user inserts into the ATM a special plastic card that is encoded with information on a magnetic strip or computer chip. The strip contains an identification code that is transmitted to the bank's central computer by modem . To prevent unauthorized transactions, a personal identification number (PIN) must also be entered by the user using a keypad. For additional security, transactions made with a computer chip also create a unique code for each transaction; this helps prevent information stolen during the transaction from being reused. Once the transaction is authorized, the computer permits the ATM to complete the transaction; most machines can dispense cash, accept deposits, transfer funds, and provide information on account balances. Transactions at ATMs may also now be done using smartphones and a number of different methods, or using palm- or fingerprints for personal identification. Banks have formed cooperative, nationwide networks so that a customer of one bank can use an ATM of another for cash access; by 2010 there were more than 420,000 ATMs across the United States. The internationalization of banking networks also permits ATM cards to be used to make transactions abroad. Some ATMs will also accept credit cards for cash advances. The first ATM was installed in 1969 by Chemical Bank at its branch in Rockville Centre, N.Y. A customer using a coded card was dispensed a package containing a set sum of money.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

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