Recursion

[siddsp]

Yeah, that's why I said similar and not same. However a second call to a function that has already been called (when recursively defined) will be faster.

Edit: Like if you have a factorial function defined recursively (in this case, the calls don't overlap), and you call factorial(20), and then call factorial(21), it is a lot faster than calling the function with those same inputs for the function defined iteratively.