| a Web site that has been copied to another server in order to provide faster access or wider availability, or to reduce network traffic. |

| mirror site n. A file server that contains a duplicate set of files of another file server, thereby sharing the burden of distribution to ensure rapid availability of data when there is heavy demand. |
mirror site networking
An archive site or website which keeps a copy of some or all files at another site so as to make them more quickly available and to reduce the load on the source site.
It is generally best to use the mirror that is physically closest to you as this will usually give the fastest download.
Such mirroring is usually done for specific whole directories or files on a specific remote server as opposed to a cache or proxy server which keeps copies of everything that is requested via it.
For example, src.doc.ic.ac.uk is the main UK mirror for the GNU archive at gnu.org.
(2006-10-16)