The two-pointer technique is widely used in competitive programming to solve array and string-related problems efficiently. It involves setting two pointers at different positions—often one at the beginning and one at the end of the array—and moving them based on specific conditions. This technique is particularly useful for problems like finding pairs that sum to a target, reversing a string, or merging intervals. By moving two pointers instead of using nested loops, the approach often reduces the time complexity from O(n^2) to O(n), making it much faster. Two-pointer problems can also involve finding subarrays or solving for conditions within arrays with minimal passes, and mastering this approach can greatly improve problem-solving speed in competitions.