What is recursion in programming?

Recursion in programming refers to a technique where a function calls itself to solve smaller instances of the same problem until reaching a base case. This helps in breaking down complex problems into simpler ones, allowing for easier problem solving and often resulting in cleaner and more intuitive code.

When a recursive function is invoked, it processes a task, and if the task requires further breakdown, it calls itself with updated parameters. This continues until the base case is met, at which point the function begins to return values back through the chain of calls. Examples of problems that are often solved using recursion include calculating factorials, traversing data structures like trees, and solving puzzles like the Tower of Hanoi.

The other choices describe different programming concepts. Iteration refers to repeating a block of code using loops, error handling is a mechanism to respond to runtime errors, and enhancing graphic user interfaces typically involves design and layout strategies rather than recursion.