What is the principle behind Quick Sort?

The principle behind Quick Sort is centered on the selection of a 'pivot' element from the array and then partitioning the array based on that pivot. In this sorting algorithm, the elements are rearranged so that those less than the pivot come before it and those greater come after it. This process of partitioning is recursive, as the Quick Sort algorithm is applied to the sub-arrays formed by splitting at the pivot. This enables an efficient average-case time complexity of O(n log n).

This method contrasts with other sorting techniques. For instance, some algorithms divide the array into two halves and sort them separately, which is typical of Merge Sort rather than Quick Sort. Additionally, checking each element sequentially to find a target refers to a linear search method, not a sorting method. Utilizing a hash table for quick look-ups does not pertain to sorting but rather to efficient data retrieval and access. Therefore, the essence of Quick Sort primarily lies in its pivot-based partitioning approach, which is captured in the correct answer.