difference between let rec and let?

This is a discussion on difference between let rec and let? within the ml forums in Programming Languages category; what is the difference between "let rec" and just "let"? what does rec stand for? are the following defintions exactly the same? at least they seem to give the same results... # let rec cube x = x*x*x;; val cube : int -> int = <fun> # cube 12;; - : int = 1728 # let cubex x = x*x*x;; val cubex : int -> int = <fun> # cubex 12;; - : int = 1728 #...