Final answer:
The two types of semaphores are binary semaphores, which manage access to single resources (similar to mutexes), and counting semaphores, which manage multiple identical resources.
Step-by-step explanation:
The two kinds of semaphores are binary and counting semaphores. A binary semaphore is essentially a mutex. It can only take the values 0 or 1 and is used to manage access to a single resource in a concurrent system. A counting semaphore, on the other hand, can take on a range of values and is used to control access to a given number of identical resources or to handle synchronization problems where there are multiple instances of a resource.