Bucket sort is a non-comparing sorting algorithm. It can be very efficient for sorting closed small ranged numbers. Because, it running time is O(dn), where d is the difference between minimum and maximum input value. It uses queue as bucket for each position. If the numbers are arbitrary without any range or the range is too high, this sorting algorithm is not preferred. Because, it will take huge amount of memory for inputs with large range.

Merge sort is a popular sorting algorithm with running time of O(n long n). It recursively splits the array in parts, sorts each part, then merges them. This strategy is known as divide an conquer algorithm.

Bubble sort is very popular and one of the easiest sorting algorithms available. It passes over the array several times (actually less than the number of elements in the array). At each pass, it compares two consecutive elements and swaps them if necessary. It has worst case running time of O(n^2) and best case running time of O(n).

Merge sort is an O(n log n) comparison-based sort algorithm. In most implementations it is stable, meaning that it preserves the input order of equal elements in the sorted output. The algorithm uses the a divide and conquer algorithmic paradigm.

Invented by John von Neumann in 1945.