به نقل از: http://www.ubuntu.com/products/whatisubuntu/serveredition (http://www.ubuntu.com/products/whatisubuntu/serveredition)
Ubuntu Server features no graphical user interface as it's primary focus is to be running as little processes as possible and to avoid the security risks of adding more. Desktops are powered down all the time where you want a server to be up 24/7 365 days a year. Stability and security is a huge priority on the server addition (on the desktop too, of course). When picking a server it is best to go with a LTS release (Long term support) as these are supported for 5 years on the server and 3 years on the desktop.