Which sorting algorithm works by repeatedly swapping adjacent elements?

Bubble sort is the algorithm that operates by repeatedly swapping adjacent elements to bring the largest or smallest values to the appropriate end of the list. The fundamental mechanism of bubble sort entails comparing each pair of adjacent elements and swapping them if they are in the wrong order. This process continues through multiple passes over the data until no more swaps are needed, indicating that the list is sorted.

The distinguishing characteristic of bubble sort is its simplicity and the way it increments through the list repeatedly, which can lead to a higher time complexity in terms of efficiency, specifically O(n^2) in the average and worst-case scenarios. However, its straightforward approach often serves educational purposes well, making it easier to grasp basic sorting concepts.

In contrast, heap sort utilizes a binary heap data structure for efficient sorting, insertion sort builds a sorted section of the array gradually, and selection sort repeatedly selects the smallest or largest element from the unsorted portion for placement in order. These alternative algorithms do not rely on the adjacent swapping mechanism that defines bubble sort.