"CACHE"............
in TI world cache memory is very important area.but lot of people haven't perfect idea in this area. i think if u can get some better idea follow this blog...

Cache Memory

Cache is a component that improves performance by transparently storing data such that future requests for that data can be served faster.

It has several types

CPU Cache -

Small memories on or close to the CPU can operate faster than the much larger main memory.

DISK Cache -

While CPU caches are generally managed entirely by hardware, a variety of software manages other caches. The page cache in main memory, which Is an example of disk cache, is managed by the operating system kernel.

WEB Cache -

is the Caching of web document to reduce bandwidth usage, server load, and perceived lag. A web cache stores copies of documents passing through it ,subsequent requests may be satisfied from the cache if certain conditions are met.