Electronic Credit card

The technology behind a credit card is quite simple, it uses a magnetic stripe similar in composition used in magnetic tapes. The magnetic stripe behind the credit card is a three track system that stores binary digit data (ones and zeros) that will be later read, decoded, verified or written by a machine loaded with a designated software.

At a Point of Sale terminal, after the card has been swiped, the software interprets the binary digit data contained on the magnetic stripe and contacts an acquiring bank or company that will respond if they will guarantee a payment from the swiped card.
Acquirers make money from interest charges made on their card or from transaction fees coming from merchants. For more on the origins of the credit card go here.


Companies
Visa Inc.. ( NYSE: V) United States
Mastercard. (NYSE: MC) United States
American Express. (NYSE: AXP) United States
Discover Financial (NYSE: DFS) United States