MERCHANT ACQUIRING SOLUTION
A Merchant Acquirer is (normally) a bank who will provide the following services to the retailer. An average retailer wishes to accept cards from a number of card schemes. The major activities carried out are :

Provide a single interface to the scheme for all card related matters

Card authorizations

Recovering money from the card issuing bank

Club card checks

Pay all the scheme and issuer fees on behalf of the merchant

Act as an intermediary in the event of card claims, returns and refunds
Merchant Acquirer acts like a large switch protecting the merchant from having to understand the detail of all the different card schemes (VISA, Maestro, etc.).