How does Java achieve synchronization? Given an class with Synchronized method A and B, a normal method C, there are 2 threads, one instance, can thes

How does Java achieve synchronization? Given an class with Synchronized method A and B, a normal method C, there are 2 threads, one instance, can these two threads call A at the same time? call A and B at the same time? A & C at the same time?
A&C yes, others no, java create instance on the heap which is shared by all threads, A and B can access the same shared resource, so at one time only one function can be executed. One instance is shared resource