I have heard companies running one website on farms of servers or say many servers. If this was true, then how it is pssible or how is it done using linux ? It has confused me for sometime. Thank you for any answers.

my guess is your talking about a Cluster

I think something like that can be done in dns as well, 'round robin', taking turns, that sort of thing, though its been awhile since I messed with dns. The real trick is in having the exact same content from all the servers. Easiest thing would be some sort of nfs, where content is read/written/uploaded/deleted/etc to one master file server that they all access, though if the object of the exercise was load balancing, that doesn't seem optimal. Some sort of caching as well? It's doable, obviously, but presents its own set of problems.

You can also do this with squid (proxy) along with jesred for redirection. So, for example twantrd.com would go to box#1 while test.twantrd.com would go to box#2 and so forth.

-twantrd