There lies a history behind the term. In general, it is an alternative for the small business funding. If to be more concrete, a creditor does a one-time payment in exchange for the future credit card sales. Such financial operation was structured at first.
But as time went by, a meaning of the term has widened. Now it means different kinds of small business funding with a set of certain characters. These refer mostly to the terms shortness and regularity of the small payments. Sometimes the term is also used for the short-term business loans.