n+1 architecture

[reachtechnocrat]

What is n+1 architecture? Ok it sounds like there will be n machines connected to one power line and one additional machine on a different one that serves as a backup. This is least expected for failover but what is the big deal about the buzzword n+1.

If not n+1 what are the other types of architectures?

I am a novice about data centers and hence this question. I googled but not much info was found.

[juniper]

N+1 meens you have (1) server that is waiting in failover to take over for any one of multiple servers (N), this is apposed to having a redundant server for each main server which would be N+N LOL!. To look at it a different way the one failover server will pick up where any failed server left off (applications, user connections, etc) so it is really impressive opposed to making multiple duplicate servers for failover and much cheaper.