The only real difference between a Semaphore and a Mutex is 
that a Semaphore can have a count > 1. While a mutex will 
only let one owner attempt access, a Semaphore can be 
assigned a number and allow "x" number of threads access.


..........Let me know if it's wrong!

you are partly right,but you must mention mutex is  binary 
semaphore.
Shemaphores are of two types , binary and counting.counting 
shemaphore can range over an unrestricted domain ,where as 
binary semaphore which is also known as mutex can range 
between 0 and 1.

Mutex: Nothing but a binary semaphore.
Mutex definition says "Mutex can lock any number of times, 
and also it should unlock any number of times"---meaning,
in re-entrant codes if recursive is used.

In this case it will lock number of times and also should 
unlock same number of times.

Semaphore: i think its default-----reeated answers.

well its true that mutex is a binary semaphore having value 
1 or 0
but mutex also define that when a producer is producing 
something consumer is not allowed to consume at that 
time.........
where as semaphore is the locking mechanism which have non 
negative integers