An ATM card is any card that can be used in Automated Teller Machines (ATMs) for transactions such as deposits, cash withdrawals, obtaining account information, and other types of transactions, often through interbank networks. ATM cards are part of a payment system issued by financial institutions, such as a bank, to a customer that enables its owner (the cardholder) to access the funds in his designated bank account(s).
A debit card is any card that can be used to make a purchase and funds are withdrawn directly from the cardholder's bank account.
The use of debit cards has become widespread in many countries and has overtaken use of cheques, and in some instances cash transactions, by volume. Like credit cards, debit cards are used widely for internet purchases.
Most Banks issue ATM-cum-Debit Cards, which can be used for withdrawing cash from Automated Teller Machines (ATMs) by debit to the cardholers account with the card issuing bank and also to make a purchase online or otherwise.
ATM-cum-Debit card is usually a smart card that contains a unique card number and some security information such as an expiration date with a magnetic strip on the back enabling various machines to read and access information. The card can be used as an ATM card, enabling transactions at automatic teller machines or as a debit card, linked to the client's bank account and can also be used for making purchases at the point of sale.
Payment cards are usually plastic cards, 85.60 mm x 53.98 mm and rounded corners with a radius of 2.88-3.48 mm.
They usually also have a unique embossed card number, the cardholder's name and the card expiry date, in addition to other security features.
All ATM machines, at a minimum, permit cash withdrawals of customers of the machine's owner (if a bank-operated machine) and for cards that are affiliated with any ATM network the machine is also affiliated. They will report the amount of the withdrawal and any fees charged by the machine on the receipt. Most banks permit routine account-related banking transactions at the bank's own ATM like checking the balance of an account, changing card PIN, cheque and cash deposit etc. The facilities offered differ from bank to bank.
Source : WIKIPEDIA