The merchant acquirer will authorise your customers card transactions and see that you are paid. It will ensure that the card transactions are passed via the card schemes to your customer s card issuer. This will allow the card issuer to charge your customers for what they have bought.
Merchant acquiring in the UK is a separate service offered by most of the high street banks.
It may be easier for your acquirer and business banker to be the same. As a starting point, you can ask the bank you have your business account with for information. These are likely to be contained in a separate agreement that you may also need to sign. Obviously before you start to accept card payments over the Internet you must make sure that your computer systems are secure. This is an organisation which is authorised by acquirers and will have the equipment and expertise to supply to merchants who do not want to invest in their own secure servers.