A credit card is a system of payment named after the small plastic card issued to users of the system. A credit card is different from a debit card in that it does not remove money fro
m the user's account after every transaction. In the case of credit cards, the issuer lends money to the consumer (or the user). It is also different from a charge card (though this name is sometimes used by the public to describe credit cards), which requires the balance to be paid in full each month. In contrast, a credit card allows the consumer to 'revolve' their balance, at the cost of having interest charged. Most credit cards are the same shape and size, as specified by the ISO 7810 standard.When a purchase is made, the credit card user agrees to pay the card issuer. The cardholder indicates their consent to pay, by signing a receipt with a record of the card details and indicating the amount to be paid or by entering a Personal identification number (PIN). Also, many merchants now accept verbal authorizations via telephone and electronic au
thorization using the Internet, known as a Card not present (CNP) transaction.Electronic verification systems allow merchants to verify that the card is valid and the credit card customer has sufficient credit to cover the purchase in a few seconds, allowing the verification to happen at time of purchase. The verification is performed using a credit card payment terminal or Point of Sale (POS) system with a communications link to the merchant's acquiring bank. Data from the card is obtained from a magnetic stripe or chip on the card; the latter system is in the United Kingdom commonly known as Chip and PIN, but is more technically an EMV card.
Other variations of verification systems are used by eCommerce merchants to determine if the user's account is valid and able to accept the charge. These will typically involve the cardholder providing additional information, such as the security code printed on the back of the card, or the address of the cardholder.
Each month, the credit card user is sent a statement indicating the purchases undertaken with the card, any outstanding fees, and the total amount owed. After receiving the statement, the cardholder may dispute any charges that he or she thinks are incorrect (see Fair Credit Billing Act for details of the US regulations). Otherwise, the cardholder must pay a defined minimum proportion of the bill by a due date, or may choose to pay a higher amount up to the entire amount owed. The credit provider charges interest on the amount owed (typically at a much higher rate than most other forms of debt). Some financial institutions can arrange for automatic payments to be deducted from the user's bank accounts.
Credit card issuers usually waive interest charges if the balance is paid in full each month, but typically will charge full interest on the entire outstanding balance from the date of each purchase if the total balance is not paid.
For example, if a user had a $1,000 outstanding balance and pays it in full, there would be no interest charged. If, however, even $1.00 of the total balance remained unpaid, interest would be charged on the $1 from the date of purchase until the payment is received. The precise manner in which interest is charged is usually detailed in a cardholder agreement which may be summarized on the back of the monthly statement. The general calculation formula most financial institutions use to determine the amount of interest to be charged is APR/100 x ADB/365 x number of days revolved. Take the Annual percentage rate (APR) and divide by 100 then multiply to the amount of the average daily balance divided by 365 and then take this total and multiply by the total number of days the amount revolved before payment was made on the account. Financial institutions refer to interest charged back to the original time of the transaction and up to the time a payment was made, if not in full, as RRFC or residual retail finance charge. Thus after an amount has revolved and a payment has been made that the user of the card will still receive interest charges on their statement after paying the next statement in full (in fact the statement may only have a charge for interest that collected up until the date the full balance was paid...i.e. when the balance stopped revolving).[1]
The credit card may simply serve as a form of revolving credit, or it may become a complicated financial instrument with multiple balance segments each at a different interest rate, possibly with a single umbrella credit limit, or with separate credit limits applicable to the various balance segments. Usually this compartmentalization is the result of special incentive offers from the issuing bank, either to encourage
balance transfers from cards of other issuers, or to encourage more spending on the part of the customer. In the event that several interest rates apply to various balance segments, payment allocation is generally at the discretion of the issuing bank, and payments will therefore usually be allocated towards the lowest rate balances until paid in full before any money is paid towards higher rate balances. Interest rates can vary considerably from card to card, and the interest rate on a particular card may jump dramatically if the card user is late with a payment on that card or any other credit instrument, or even if the issuing bank decides to raise its revenue. As the rates and terms vary, services have been set up allowing users to calculate savings available by switching cards, which can be considerable if there is a large outstanding balance (see external links for some on-line services).Because of intense competition in the credit card industry, credit providers often offer incentives such as frequent flier points, gift certificates, or cash back (typically up to 1 percent based on total purchases) to try to attract customers to their program.
Low interest credit cards or even 0% interest credit cards are available. The only downside to consumers is that the period of low interest credit cards is limited to a fixed term, usually between 6 and 12 months after which a higher rate is charged. However, services are available which alert credit card holders when their low interest period is due to expire. Most such services charge a monthly or annual fee.
Grace period
after certain conditions are met. Usually, if a customer is late paying the balance, finance charges will be calculated and the grace period does not apply. Finance charge(s) incurred depends on the grace period and balance, with most credit cards there is no grace period if there's any outstanding balance from the previous billing cycle or statement (ie. interest is applied on both the previous balance and new transactions). However, there are some credit cards that will only apply finance charge on the previous or old balance, excluding new transactions.A secured credit card is a type of credit card secured by a deposit account owned by the cardholder. Typically, the cardholder must deposit between 100% and 200% of the total amount of credit desired. Thus if the cardholder puts down $1000, he or she will be given credit in the range of $500–$1000. In some cases, credit card issuers will offer incentives even on their secured card portfolios. In these cases, the deposit required may be significantly less than the required credit limit, and can be as low as 10% of the desired credit limit. This deposit is held in a special savings account. Credit card issuers offer this as they have noticed that delinquencies were notably reduced when the customer perceives he has something to lose if he doesn't repay his balance.
The cardholder of a secured credit card is still expected to make regular payments, as he or she would with a regular credit card, but should he or she default on a payment, the card issuer has the option of recovering the cost of the purchases paid to the merchants out of the deposit. The advantage of the secured card for an individual with negative or no credit history is that most companies report regularly to the major credit bureaus. This allows for rebuilding of positive credit history. 
Although the deposit is in the hands of the credit card issuer as security in the event of default by the consumer, the deposit will not be debited simply for missing one or two payments. Usually the deposit is only used as an offset when the account is closed, either at the request of the customer or due to severe delinquency (150 to 180 days). This means that an account which is less than 150 days delinquent will continue to accrue interest and fees, and could result in a balance which is much higher than the actual credit limit on the card. In these cases the total debt may far exceed the original deposit and the cardholder not only forfeits their deposit but is left with an additional debt.
Most of these conditions are usually described in a cardholder agreement which the cardholder signs when their account is opened.
Secured credit cards are an option to allow a person with a poor credit history or no credit history to have a credit card which might not otherwise be available. They are often offered as a means of rebuilding one's credit. Secured credit cards are available with both Visa and MasterCard logos on them. Fees and service charges for secured credit cards often exceed those charged for ordinary non-secured credit cards, however, for people in certain situations, (for example, after charging off on other credit cards, or people with a long history of delinquency on various forms of debt), secured cards can often be less expensive in total cost than unsecured credit cards, even including the security deposit.
Sometimes a credit card will be secured by the equity in the borrower's home.[3][4] This is called a home equity line of credit (HELOC)....
