Proxy server

A Proxy server provides a cache of items available on other servers which are presumably slower or more expensive to access.

This term is used particularly for a World Wide Web server which accepts URLs with a special prefix. When it receives a request for such a URL, it strips off the prefix and looks for the resulting URL in its local cache. If found, it returns the document immediately, otherwise it fetches it from the remote server, saves a copy in the cache and returns it to the requester. The cache will usually have an expiry algorithm which flushes documents according to their age, size, and access history.

Based on Foldoc