Sliding window is a method for iterating over a linear collection by maintaining a window range indices (group of consecutive elements) to satisfy the problem constraints

Sliding window is an improvement over brute force iteration to reduce the time complexity

Let's see a specific example

The Maximum Subarray problem

Given an array A, write an algorithm to find the maximum sum of k consecutive elements in A

Approach 1: Brute force

Iterating over A one by one element to find max sum

Approach 2: Sliding Window

Iterating over A window by window to find max sum