Which of the following is not considered a sorting algorithm?

Depth-First Search is not considered a sorting algorithm because it is a graph traversal algorithm used primarily to explore all the nodes and branches of a graph or tree structure. Its main purpose is to reach each vertex in a graph without necessarily putting the data in a specific order. In contrast, sorting algorithms like Selection Sort, Merge Sort, and Insertion Sort are specifically designed to rearrange elements in a list or array into a certain order, typically ascending or descending based on their values. Each of these sorting algorithms follows specific methodologies to achieve this goal, whereas Depth-First Search does not involve any arrangement of data elements. This fundamental difference in purpose and function distinguishes Depth-First Search from the other options, which are all dedicated to sorting processes.