Generally, some algorithms are more easily expressed as recursive functions than iterative loops. ...and vice versa. And realistically, that's how you should choose ninety nine percent of the time.

But if you want to get into the weeds... Prefer iteration unless you know one or more of the following:

• Your maximum iteration depth is bounded and cannot overflow your machine's stack depth.
• Your algorithm can be implemented with tail-call recursion AND your language supports the same.
• Your senior/team lead wants a recursive solution.

Because in environments where none of the above are true, iterative solutions are usually more performant, safer, and better understood.