The major use of the two pointers technique is to optimize code by reducing time complexity when searching pairs in a sorted array. The technique works by using two pointers to represent the first and last elements of the array, and then adding the values kept at both pointers. If their sum is smaller than a given value, the left pointer is shifted to the right, and if their sum is greater than the given value, the right pointer is shifted to the left. The two pointers technique can also be used to traverse a linked list, find the middle element, merge intervals, and determine if a string is a palindrome, among other applications.