When and why to play e5 or c5 in the KID

Can someone help me understand the differences in position that allow players to play e5 instead of c5? I understand when to play it through opening prep, but I don't know the why or the how of it.

You can always play c5 when you like Benoni.

It really depends on how you would like to play, but I usually play e5 whenever it is safe.
When it comes to c5, I might play it if White abstains from the main lines but otherwise I prefer e5.