ATMs are found everywhere, usually outside of banks, and also in airports, grocery and convenience store, and shopping malls. Each ATM will be associated with a bank, but you can use any machine that is part of your bank's "network." Look for network symbols on the back of your card, such as "CIRRUS." Your card can be used in any machine displaying these same symbols. Beware that if you use an ATM that is not owned by your bank, you may be charged a fee. Some banks even charge their own customers for use of their ATMs. This fee can be a few cents or more than a dollar, but most people think the convenience is worth it.
ATM debit cards can be used just like credit cards in many gasoline stations, discount stores, grocery stores, some restaurants and department stores. But remember that the amount of your purchase will be immediately deducted from your account balance. You'll want to keep a record of your card use.