An ATM, which stands for Automated Teller Machine, is a specialized computer that allows bank customers to access their accounts to withdraw money, make deposits, transfer funds, or check their account balances without the need for a human teller.

ATMs are typically located in public places, such as bank branches, shopping centers, and airports, and can be accessed 24 hours a day, 7 days a week. To use an ATM, customers typically insert a debit or credit card into the machine and enter a personal identification number (PIN) to verify their identity.

Here are some common functions that an ATM can perform:

• Cash Withdrawal: Dispense cash to the user.
• Deposits: Allow users to deposit cash or checks into their accounts.
• Balance Inquiry: Display the current balance of the user's account.
• Funds Transfer: Transfer funds between different accounts of the same user.
• Bill Payment: Some ATMs allow users to pay bills directly from their accounts.

For more information, you can refer to these resources:

• Investopedia - Automated Teller Machine (ATM)
• FDIC - Using ATMs