Caching lets you store web pages on the visitor's browser, intermediate proxies, and in server memory. It also lets you store data objects in server memory. This way, there is no need to regenerate these items for every individual web page request. As a result, you improve responsiveness and reduce the load on the CPU and database.
ASP.NET's caching feature is very easy-to-use, requiring only a simple line to cache a web page. Server memory is cheap, and browser and proxy memory cost you nothing. That makes caching a low cost, high-payoff way to improve performance.
This chapter takes you through the five types of caching, and shows how to use them: