You can enable output caching for an ASP.NET page by using the System.Web.HttpCachePolicy class or adding a page directive. This enumeration is used by ASP.NET when it calls the Page.InitOutputCache( ) method. It specifies whether the page is cached locally on the client (Client), on the web server (Server), or on another server between the client and the web server (Downstream).
public enum OutputCacheLocation { Any = 0, Client = 1, Downstream = 2, Server = 3, None = 4, ServerAndClient = 5 }