Quicksort is a sorting algorithm that is used to sort items in an array. It was created by Tony Hoare in 1959, and it is still widely used today. Quicksort splits the array into two parts, and then continues to split those parts into more parts, and sorting along the way. It sorts by using a comparison sort. This means that it chooses a pivot point in a part of the array and then compares it with all the other points in that part of the array.