ASP.NET Caching Features
ASP.NET Web Applications


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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. 
Retrieving information from a resource outside the 
application will require more processing steps, and will 
therefore require more time and resources on the server 
than if the information can be obtained from within the 
application space. 

If the information that will be sent to the browser has 
already been prepared by a previous request, the 
application will be able to retrieve that information 
faster if it has been stored in memory, somewhere along the 
request/response stream. 

Known as caching, this technique can be used to temporarily 
store page output or application data either on the client 
or on the server, which can then be re-used to satisfy 
subsequent requests and thus avoid the overhead of re-
creating the same information. 

Caching is particularly suitable when you expect to return 
the same information in the same format for many different 
requests. 

ASP.NET provides the following types of caching that can be 
used to build highly responsive Web applications: 

Output caching, which caches the dynamic response generated 
by a request. 
Fragment caching, which caches portions of a response 
generated by a request. 
Data caching, which allows developers to programmatically 
retain arbitrary data across requests.

there are 3 types of caches is there they ara 1)page caching
2)page fragmentaion caching3)data caching
in case of the page caching  the total page will be cached 
for certain amount of time(i.e the time will declared by 
ourself)and in case of page fragmentation caching only a 
part of the data will be cached for some amount of time
Data caching, which allows developers to programmatically 
retain arbitrary data across requests