Understand the code.
Own the next step.

This is QuickSort, a divide-and-conquer sorting algorithm. How it works: 1. Base case: arrays of 0-1 elements are already sorted 2. Pick first element as the pivot point 3. Partition: elements ≤ pivot go left, > pivot go right 4. Recursively sort both partitions 5. Combine: left + pivot + right Complexity: O(n log n) average, O(n²) worst case