A recursive step — a set of rules that reduces all successive cases toward the base case. For example, the following is a recursive definition of a person's ancestor. One's ancestor is either: One's parent (base case), or One's parent's ancestor (recursive step). The Fibonacci sequence is another classic example of recursion:
Recursive drawing of a Sierpiński Triangle through turtle graphics In computer science, recursion is a method of solving a computational problem where the solution depends on solutions to smaller instances of the same problem. [1][2] Recursion solves such recursive problems by using functions that call themselves from within their own code.