Revolving credit lines are a specific type of credit account where you have access to credit up to your credit limit. You can borrow up to your limit and when you repay, your credit limit is replenished.
Revolving credit lines work very similarly to credit cards, though they will appear as different types of accounts on your credit file.
Effectively at any point, your credit limit is available to you regardless of how many times you withdraw and repay. If the amount you owe is not paid by the due date, the balance will stay on your account and you will likely start accruing interest.