Definitions for "Server Cluster"
a collection of servers known as nodes that together provide a single, highly available system for hosting applications
a group of independent computer systems that work together as a single system
a group of independent servers interconnected to form a single computing resource
A setup in which one server holds all the files for a website or group of sites, and several other servers handle delivering the data. This is an expensive setup, but if you ever need one you'll have so much traffic that the cost will be a secondary concern for you.
Keywords:  farm, see
See Server farm.