Understanding recursion

There is a famous programming wisdom quote that says:

“To understand recursion, one must first understand recursion.”

                                                                                                      - Unknown

Recursion is a method to solve problems that consist of solving smaller portions of the same problem until you solve the original, larger problem. It usually involves calling the function itself.

A method or function is recursive if it can call itself directly, as follows:

function recursiveFunction(someParam){
  recursiveFunction(someParam);
}

A function is also called recursive if it can call itself indirectly, as follows:

function recursiveFunction1(someParam){
  recursiveFunction2(someParam);
}

function recursiveFunction2(someParam){
  recursiveFunction1(someParam);
}

Suppose we have to execute recursiveFunction. What would the result be? In this case, it would be executed indefinitely. For this reason, every recursive function must have a base...