• OPGs enable you to buy items from the comfort of your home.Jupiterimages/Comstock/Getty Images
  
  As of 2010, the majority of major retailers accept credit cards as a form of payment. If you use credit cards, you'll come across different processing terms through your vendors or your credit card company. Understanding these terms helps you manage your account more easily because they show how the credit card company and vendors are operating.
  
  

ACH

• ACH is an acronym for automated clearing house, which is an organization that clears, or processes, electronic credit/debit transactions. An ACH verifies that your card is authentic and active and makes sure that the right amount is charged to your account at the proper time.
  
  

CVV2

• A CVV2 is a security code on the back of credit cards. Most of the time, the code is a three-digit number listed on the back of the card; on certain cards, the CVV2 may be four digits. If you purchase an item online or over the phone, the vendor may ask for the CVV2 to verify that you actually have the card in front of you and that you are the card owner.
  
  

SSL/SSL Certification

• SSL stands for secure sockets layer, a method of encrypting data that travels over the Web between you and a vendor via your Internet browser. This is crucial to keeping your credit card information private as you place your order. An SSL certificate is the certificate on the server that actually handles the encryption.
  
  

Keyed

• Keyed refers to any transaction in which you manually have to enter your credit card data. Most online purchases are keyed unless the vendor is able to store your credit card information at your request. Cashiers sometimes key a transaction at the register if your card is valid but isn't accepted by the card reader.
  
  

Online Payment Gateway

• An online payment gateway (OPG), also called a virtual terminal, is a browser application that allows an online vendor to authorize your credit card payment. It connects the shopping cart to the company that processes cards for the vendor. Without OPGs, online shopping would be impossible.
  
  

POS

• POS, an acronym for point of sale, refers to the physical location at which you used your credit card. POS is important in tracking credit card history. Police can use POS records to find stolen credit cards and the individuals who have taken them.
  
  

Chargeback

• Chargebacks essentially are refunds. When there's something on your credit card statement you know you didn't authorize, you can present proof of the inaccuracy to your credit card company. The company then retracts the charge so that you have that amount left on your remaining credit balance again.