c++ - Difference between Mutex and Binary semaphore

What is the difference between Mutex and Binary semaphore?
semaphore is used to synchronize processes. where as mutex is used to provide synchronization between threads running in the same process. 

What methods can be overridden in Java? 
In C++ terminology, all public methods in Java are virtual. Therefore, all Java methods can be overwritten in subclasses except those that are declared final, static, and private.