Web Caching

web caching refers to storing locally the once referenced web objects, should any future request come for that object, it is checked for in local store and if present there it is retrieved directly from the local store instead from the original server. It saves time, bandwidth and of course money. Web caching can be done at end users desktop or on dedicated cache server. Most of the present day browsers have support for caching to some extent though they are not of high performance and limited to a computer only. the most effective way to implement cache is by service provider. they can deploy a dedicated server and high performance web caching software. Wherever caching is done the goal is the same. It is better if ISPs cache web objects so that frequently referenced sites could be serve locally instead of downloading every time from the original servers. This increases throughput dramatically. the above discussions suggests that given sufficient storage, whole internet could be cached. However this is not true, Information is dynamic in nature and so is the web. If we cache everything we end up serving stale objects to the clients. this is worse than having slow access. there are methods to ensure the freshness of an object stored in a cache.