Credit Card Terms - Revolving Credit Card Balance
Revolving balance on a credit card or even a revolving line of credit simple means the balance you carry on a credit card. The balance can vary: you purchases drive up the balance, your payments bring the balance down again, and repeat... You can use the credit at any increments up to your credit limit and typically pay back monthly the minimum amount or some other amount above the minimum payment amount - these also vary depending on the amount of your balance and interest rates etc.
Compare this to a loan which is not a revolving balance - it's a set borrowed amount, with set payments and interest rate, for a specific time period and the balance will decline incrementally until the loan is paid off.