That is the maximum loan amount. Do you need some extra money? Then you can withdraw extra credit every time you reach the credit limit. Did you pay back some money afterwards? Then you can withdraw extra money from your loan until you reach the credit limit again.
With a revolving credit, you may withdraw during the term of the loan, but also redeem as often as you wish. In consultation with the lender it is agreed what amount you have to pay at least per month. This is often a percentage of the credit limit or of the outstanding balance of the credit. But you can also pay off extra, which, unlike a personal loan, you will not be fined. In this way you shorten the term of the loan. Do you want to take extra credit in the interim? Then the term of the loan is extended again.