How does caching improve the performance of a Web browser? Does caching reduce the number of interactions that take place between the browser and the Web server?

What will be an ideal response?

When a page or image is first downloaded, it is stored in a temporary directory on the user's computer. The next time that page or image is requested, the browser first checks
to see if it has a copy stored locally in the cache, and, if so, whether the copy is up-to-date (this is accomplished by contacting the server and asking how recently the page was changed). If an up-to-date copy is stored locally, then the browser can display this copy, instead of downloading the original. Caching can make downloading a new copy unnecessary, but it still requires a check to see if the cached page is up-to-date.