Bucket sort is a fundamental programming algorithm, used to expedite the sorting process by grouping elements. In this algorithm, elements in a dataset are first divided into different categories (or "buckets"). Then, each bucket sorts the elements within it in ascending or descending order. The buckets are then recombined, with the result being a fully-sorted dataset.
Bucket sort is a little more advanced than other sorting techniques, like the bubble sort, in that it is a framework made up of other sorting algorithms. For instance, you can use one algorithm to sort elements into their buckets, and another algorithm to sort elements within their buckets.
You could even reuse the initial algorithm recursively to sort each bucket to use fewer lines of code. This flexibility makes bucket sorting slightly more complex, but also more versatile.
Bucket sort is typically used in one of two scenarios.
The first is to speed up the sorting process. The process of placing items into bins and then sorting them in smaller amounts is much faster than a linear sort such as the bubble sort. The cost, however, is that bucket sort uses more memory than linear algorithms.
The second use case for bucket sort is in assigning priority or organizing less structured datasets. For instance, bucket sort can be used to organize a to-do list, assign prioritization, or sort things by the amount of time they might take.