what is caching in asp.net?

Here is an article on caching in ASP.NET

http://www.c-sharpcorner.com/Forums/ShowMessages.aspx?ThreadID=33247

To speed up processing  we use Caching.

When clients access an ASP.NET page, there are basically two ways to provide them with the information they need:

• the ASP.NET page can either obtain information from server resources, such as from data that has been persisted to a database, or
• the ASP.NET page can obtain information from within the application.

ASP.NET supports three types of caching for Web-based applications:

• Page Level Caching (called Output Caching)
• Page Fragment Caching (often called Partial-Page Output Caching)
• Programmatic or Data Caching