Definition of Invoice Finance?

It's pretty simple, really.

To raise cash, you sell some of your credit invoices to a financier. The financier pays you (now), and the customer pays the financier (later).

That's it. That's Invoice Finance.

It's not the same as Debt Factoring, but could be considered a near relative. You might also hear it referred to as Debtor Finance, Invoice Discounting and Spot Factoring.

For more detailed explanations, check out these Wiki links:
Invoice Discounting or Factoring