Debit card

A debit card (also known as a bank card or check card) is a plastic card that provides an alternative payment method to cash when making purchases. Functionally, it can be called an electronic check, as the funds are withdrawn directly from either the bank account, or from the remaining balance on the card. In some cases, the cards are designed exclusively for use on the Internet, and so there is no physical card.
In many countries the use of debit cards has become so widespread that their volume of use has overtaken or entirely replaced the check and, in some instances, cash transactions. Like credit cards, debit cards are used widely for telephone and Internet purchases and, unlike credit cards, the funds are transferred immediately from the bearer's bank account instead of having the bearer pay back the money at a later date.
Debit cards may also allow for instant withdrawal of cash, acting as the ATM card for withdrawing cash and as a check guarantee card. Merchants may also offer cashback facilities to customers, where a customer can withdraw cash along with their purchase.




Advantages and disadvantages

Advantages 
A consumer who is not credit worthy and may find it difficult or impossible to obtain a credit card can more easily obtain a debit card, allowing him/her to make plastic transactions.
For most transactions, a check card can be used to avoid check writing altogether. Check cards debit funds from the user's account on the spot, thereby finalizing the transaction at the time of purchase, and bypassing the requirement to pay a credit card bill at a later date, or to write an insecure check containing the account holder's personal information.
Like credit cards, debit cards are accepted by merchants with less identification and scrutiny than personal checks, thereby making transactions quicker and less intrusive. Unlike personal checks, merchants generally do not believe that a payment via a debit card may be later dishonored.
Unlike a credit card, which charges higher fees and interest rates when a cash advance is obtained, a debit card may be used to obtain cash from an ATM or a PIN-based transaction at no extra charge, other than a foreign ATM fee.
 Disadvantages

Use of a debit card is not usually limited to the existing funds in the account to which it is linked, most banks allow a certain threshold over the available bank balance which can cause overdraft fees if the users transaction does not reflect available balance.
Many banks are now charging over-limit fees or non-sufficient funds fees based upon pre-authorizations, and even attempted but refused transactions by the merchant (some of which may be unknown until later discovery by account holder).
Many merchants mistakenly believe that amounts owed can be "taken" from a customer's account after a debit card (or number) has been presented, without agreement as to date, payee name, amount and currency, thus causing penalty fees for overdrafts, over-the-limit, amounts not available causing further rejections or overdrafts, and rejected transactions by some banks.
In some countries debit cards offer lower levels of security protection than credit cards[9]. Theft of the users PIN using skimming devices can be accomplished much easier with a PIN input than with a signature-based credit transaction. However, theft of users' PIN codes using skimming devices can be equally easily accomplished with a debit transaction PIN input, as with a credit transaction PIN input, and theft using a signature-based credit transaction is equally easy as theft using a signature-based debit transaction.
In many places, laws protect the consumer from fraud much less than with a credit card. While the holder of a credit card is legally responsible for only a minimal amount of a fraudulent transaction made with a credit card, which is often waived by the bank, the consumer may be held liable for hundreds of dollars, or even the entire value of fraudulent debit transactions. The consumer also has a shorter time (usually just two days) to report such fraud to the bank in order to be eligible for such a waiver with a debit card[9], whereas with a credit card, this time may be up to 60 days. A thief who obtains or clones a debit card along with its PIN may be able to clean out the consumer's bank account, and the consumer will have no recourse.
 
Financial access

Debit cards and secured credit cards are popular among college students who have not yet established a credit history. Debit cards may also be used by expatriated workers to send money home to their families holding an affiliated debit card.

Issues with deferred posting of offline debit

To the consumer, a debit transaction is perceived as occurring in real-time; i.e. the money is withdrawn from their account immediately following the authorization request from the merchant, which in many countries, is the case when making an online debit purchase. However, when a purchase is made using the "credit" (offline debit) option, the transaction merely places an authorization hold on the customer's account; funds are not actually withdrawn until the transaction is reconciled and hard-posted to the customer's account, usually a few days later. However, the previous sentence applies to all kinds of transaction types, at least when using a card issued by a European bank. This is in contrast to a typical credit card transaction; though it can also have a lag time of a few days before the transaction is posted to the account, it can be many days to a month or more before the consumer makes repayment with actual money.

Because of this, in the case of a benign or malicious error by the merchant or bank, a debit transaction may cause more serious problems (e.g. money not accessible; overdrawn account) than in the case of a credit card transaction (e.g. credit not accessible; over credit limit). This is especially true in the United States, where check fraud is a crime in every state, but exceeding your credit limit is not.

Overdraft fees

A 2007 Washington Post article — on banks' lucrative debit card overdraft fees — pointed out that debit card issuers could notify customers electronically, allowing them to avoid overdraft fees. Nessa Feddis, banking industry spokesperson and lobbyist, contended that "current technology makes real-time notification of overdrafts cost-prohibitive.he article contended that "financial institutions don't want to change the status quo because they make good and easy money off their own customers' mistakes and irresponsibility.