The "sliding window" technique is a method used in computer science and programming to efficiently manage a subset of data within a larger dataset. It involves maintaining a window that can expand or contract as needed, allowing for the examination of a continuous segment of data without the need to repeatedly process the entire dataset. This approach is particularly useful in problems involving arrays or strings, where you need to analyze or manipulate a sequence of elements. In practice, the sliding window technique can optimize algorithms by reducing time complexity. For example, when calculating the maximum sum of a subarray of fixed size, the window can slide one element at a time, updating the sum incrementally rather than recalculating it from scratch. This method is commonly applied in various algorithms, including those related to arrays, strings, and dynamic programming.