The difference between recursion and induction

definition

What is the difference between recursion and induction? I have heard those terms used interchangeably, but I was wondering if there is a difference between them, and if so, what the difference is.

Best Answer

In my experience:

  • "Recursion" is a way of defining some mathematical object (including a function or computation whose definition involves a recursive algorithm);
  • "Induction" is a way of proving some mathematical statement.

Extremely often, if a mathematical statement is made about a recursively-defined object, then the proof of that statement will involve induction.

For example, the definition of the Fibonacci numbers is a recursive definition. The proof of the assertion that the $n$th Fibonacci number is at most $2^n$ is an inductive proof.