It means you can choose either to extend or stop the lease. You will probably let the landlord know.

한가지 더 물어볼께 있습니다 렌트비는 4년이 끝났을때 랜로드가 올릴수 있는가요?
아니면 5년까지 끝났을때 올릴수 있는가요?

It depends on your contract.
The rent can be raised every year unless it is written as fixed on your contract. It could be like 3% increase a year, or according to CPI(consumer price index).
Check your contract or ask your broker if you don’t have a contract yet.