Recursion vs loops

Recursion and iteration are two tools that, at a very fundamental level, do the same thing: execute a repeated operation over a defined set of values. They are interchangeable in that there is no problem that cannot, in some way, be solved by only one of them. That does not mean, however, that one cannot be more suited than the other.

In my experience, most recursive solution can indeed be solved iteratively.

It is also a good technique to have, as recursive solutions may have too large an overhead in memory and CPU consumptions.

The only difference between iteration and recursion on a computer is whether you use the built-in stack or a user-defined stack. So they are equivalent.

Since recursion uses an implicit stack on which it stores information about each call, you can always implement that stack yourself and avoid the recursive calls. So yes, every recursive solution can be transformed into an iterative one.

Read this question for a proof.