Binary Semaphore
A binary semaphore is a synchronization object that has two states: 0 and 1. It is used to control access to a shared resource where only one process or thread can access the resource at a time. The binary semaphore can be viewed as a lock that is either open (1) or closed (0). When a process or thread wants to access the shared resource, it must acquire the semaphore (set it to 0). If the semaphore is already set to 0, the process or thread is blocked until the semaphore is released (set to 1) by another process or thread.
Counting Semaphore
A counting semaphore is a synchronization object that has an integer value that can be incremented or decremented by a process or thread. It is used to control access to a shared resource where a fixed number of processes or threads can access the resource at the same time. The counting semaphore can be viewed as a set of locks, where the number of locks is equal to the value of the semaphore. When a process or thread wants to access the shared resource, it must acquire one of the locks (decrement the semaphore value). If all the locks are already taken, the process or thread is blocked until one of the locks is released (increment the semaphore value) by another process or thread.