What does recursion refer to in programming?

Recursion in programming refers to a technique where a function calls itself to solve a problem. This approach allows complex problems to be broken down into smaller, more manageable sub-problems, which can then be solved more easily.

In practical terms, a recursive function usually has two main components: the base case, which defines when the recursion should stop, and the recursive case, which is the logic that continues to call the function with modified arguments. For example, calculating the factorial of a number can be done using recursion by multiplying the number by the factorial of the number minus one until it reaches one.

This method is powerful for problems that have a natural recursive structure, such as tree traversal, combinatorial problems, and many others. It provides an elegant solution that may be clearer and simpler to implement than an iterative approach in some cases.