The purpose of a browser cache is to store copies of web pages, images, and other resources locally on a user's device. This stored data allows for quicker access to frequently visited sites, significantly reducing load times and improving overall browsing performance. By maintaining a cache, a browser minimizes the need to download the same resources repeatedly, which also decreases bandwidth consumption. While beneficial for user experience, cache management is crucial to ensure that users access the most up-to-date content from the sites they visit.