What is recursion in programming?

Recursion in programming refers to a technique where a function calls itself, allowing it to solve problems by breaking them down into smaller, more manageable subproblems. This is particularly useful for tasks that can be divided into similar tasks, such as calculating factorials, traversing tree structures, or solving problems based on the divide-and-conquer strategy.

When a function uses recursion, it typically includes a base case that stops the recursion when a certain condition is met, and a recursive case where the function continues to call itself with modified arguments to approach that base case. This allows the solution to be built incrementally, processing smaller pieces of the overall problem at each step.

This understanding of recursion captures its essence and practical applications effectively, distinguishing it from other programming techniques, such as creating new instances of functions, calling multiple functions simultaneously, or storing results in a database, none of which accurately embody the core concept of recursion.