What is difference between entry controlled loop and exit controlled loop?

Question :

What is difference between entry controlled loop and exit controlled loop?

In an entry-controlled loop, the loop control condition is evaluated at the entry point of the loop. However, in an exit-controlled loop, the loop control condition is evaluated at the exit point of the loop. 
If the loop control condition is false in the beginning, the entry-controlled loop is never executed, however, the exit-controlled loop would be executed at least once.