Hi,
One way to improve the performance of any Web application is to cache static
content in memory. Cached content is always returned faster than freshly
rendered content. However, the tradeoff is that cached content may become
stale. ASP.NET 1.x supports several kinds of caching including:

Page level—Each page may be cached as a whole piece or based on the
parameters used to access the page. The cached page expires after a fixed
time.
Page fragment—If the page was built with user controls (.ascx files), then
the user controls could be cached independently of the rest of the page
content.
Programmatic caching—The developer could also cache objects thanks to the
cache API. The cache API offers the distinct advantage of providing a means
to create different types of dependencies for when the cache should be
flushed.

Hope this answers your query.

References :msdn site.

Thanks and Regards,
Manish Bafna.
MCP and MCTS.