Any person, organization or company that accepts credit or debit card payments that are properly presented is a merchant. This can include a retailer, an online seller, a charity or any other kind of organization that hold a merchant account and participates in a merchant agreement.
The merchant account is the business agreement between any kind of merchant and a credit card processor that allows the merchant to accept credit or debit payment cards from a customer or client. The merchant account is subject to various terms and conditions.
The merchant agreement is the entirety of the agreement between a merchant and an acquirer and spells out in great detail the responsibilities, rights and warranties involved in the relationship. When written properly, the merchant agreement covers all possibilities and eventualities and covers all aspects of the relationship between the two parties.
Also called the acquirer, the merchant bank is the bank that a merchant uses to complete credit card and ACH transactions as well as some other kinds of payments. The merchant bank is the first step in the transaction process after the payment is accepted by the merchant.