server farm : Java Glossary

Large corporations such as Google, or large ISPs (Internet Service Providers) have roomfuls of servers. Their main cost is the AC (Alternating Current) power. They seek out low power rack-mounted equipment. Applications run on many servers. If a server fails, others rapidly take up the load. If a server becomes overloaded, other servers rapidly absorb the load.

Sometimes server farms are distributed in many different locations. This avoids putting too many eggs in one basket and makes it possible for a server to be closer to the end user and hence more responsive. Such a server farm is called a cloud.