clustered

[TeamTimmy]

What exactly is clustered web hosting?

[suwunk]

Clustered hosting is a type of web hosting that spreads the load of hosting across multiple physical machines ("nodes"), increasing availability and decreasing the chances of one service (e.g., FTP or email) affecting another (e.g., MySQL). Many large websites run on clustered hosting solutions, for example, large discussion forums will tend to run using multiple front-end webservers with multiple back-end database servers.
Source: wikipedia