What is web-caching?

Answer 1

Web caching is the caching of web documents (e.g., HTML pages, images) in order 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. Actuality not all of the documents will be stored in it, but just the most common webs that most of the clients load it,because the memory size of the web caching is smaller than the memory size in server.