Unfortunately, "fraud" has become a widespread term and the most painful problem for on-line business. Literally fraud means theft, cheating, violation. All e-commerce merchants should be ready to face fraudsters, as cyber criminal turned to be the most tricky and popular way to obtain money.
Mostly fraudulent transactions are made with lost or stolen cards, when criminals use stolen payment information to make purchases online or when customers make a purchase and then dispute the transaction (in other words they issue chargeback) claiming they didn't receive the order \ it was damaged \ they didn't make a transaction.
Credit card fraud operations are becoming more advanced due to digital devices rapid progress - that is why it is important to have the proper fraud prevention measures.