ReentrantReadWriteLock: what's the difference between ReadLock and WriteLock?

Question

What I know is:

• ReadLock and WriteLock affect each other somehow
• WriteLock is just like synchronized
• ReadLock

Answer 1

When a thread acquires a WriteLock, no other thread can acquire the ReadLock nor the WriteLock of the same instance of ReentrantReadWriteLock, unless that thread releases the lock. However, multiple threads can acquire the ReadLock at the same time.