Tail Recursion

If an argument calls itself as its last action, the function's stack frame can be reused. This is called tail recursion. These are iterative processes and executive much like a loop.

However, if we have a function such as factorial(n) that calls n*factorial(n-1) last, it does not act as a tail recursive function.

It's best to refactor a function so that it is tail recursive because the JVM will only allow about 1000 stack frames to be used.