The Colocation centre reference article from the English Wikipedia on 24-Jul-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Colocation centre

For thoughtful child sponsors
A colocation centre ("colo") or carrier hotel is a type of data center where multiple telecommunications network or service providers, such as telcos or ISPs, site their connections to one another's networks (points of presence).

Most peering points are sited in colocation centres.

These sites are often used for web hosting.

Most colocation centres have high levels of physical security and multiple redundant power and air-conditioning systems.