What is a revolving line of credit?

Buyers are able to make purchases with their preferred vendor using credit.

You are given a credit limit when your application is approved. Buyers are able to make purchases up to their credit limit, but their buying power is reduced as more purchases are made.

Once you pay down your invoices, your credit limit is restored and your buying power goes back to the full amount.

This cycle continues as you make purchases and pay off your invoices, hence a "revolving" line of credit.