Buying future credit and debit card sales.
Merchant Advance Capital will buy (for example) $50,000 of your future sales for $40,000 today. They'll take 5% of each sale until they get repaid the full $50,000.
Factoring
Paying cash up front to buy a client's accounts receivable contracts for approximately 80% of the contracts value. The factor then waits for payment and performs all necessary legwork to remind the debtor client that the bill remains outstanding.
Once the factor gets paid in full, its staff deducts a fee that tends to be between 2-5% of the contract's value. The factor then sends the remaining money back to the client.