The document describes the bubble sort algorithm. It takes an array of numbers as input, such as {1,3,5,2,4,6}, and sorts it in ascending order through multiple passes where adjacent elements are compared and swapped if in the wrong order, resulting in the sorted array {1,2,3,4,5,6}. The algorithm works by making multiple passes through the array, swapping adjacent elements that are out of order on each pass until the array is fully sorted.