What is a farm, as opposed to a grid or a cluster?

Question

I'm trying to understand does "farm" mean in computing, so that, if a farm can be exemplified as a cluster, there must be something that a farm is independently of what a cluster is.

How is it different than a grid?

Do these concepts have a general meaning, where talking about for example web servers is only one common scennario, or do they differ deppending on the context completely? If so, what are the different meanings (or the most common ones)?

Also, should I be asking this somewhere else? (If so, my apologies).

Answer 1

I'll have a go:

A server farm is a group of servers, which may or may not be clustered, that together offer a higher computing capacity for a particular goal than an individual server. An example is a Web farm, which typically consists of a number of load-balanced Web servers, each with the same content and configurations.

While a farm may be clustered, typically a cluster consists of servers that are configured in a failover scenario, for instance active/passive, meaning that, say, 1/2 the servers are on active duty while the rest becomes activated only when the servers on active duty are no longer accessible. So when a server in the cluster crashes, it is not a problem because another server takes over.

A grid then is typically a configuration of computers that work together (in parallel) to solve a complicated task, such as organic chemistry computations or playing chess against the world champion. The work is divided into parts and each computer takes on a part and reports its findings to the main node which then synthesizes the final result.

I hope this helps.

Some links:

Wikipedia definition of server farm: http://en.wikipedia.org/wiki/Server_farm

Wikipedia definition of computing cluster: http://en.wikipedia.org/wiki/Cluster_(computing)

Wikipedia definition of grid computing: http://en.wikipedia.org/wiki/Grid_computing