What kind of motherboard has multiple CPUs and a lot of RAM and is sometimes seen in a networking rack?

Although, they appear to be the same as normal computers, servers are typically utilized to carry out more tasks (which are ofter harder and heavier) than any other computers on the same network, especially in a virtualization environment.
Because of its intended tasks, a server is typically equipped with better processing power and more RAM, and it will be rack-mounted, so that technicians could get access easily in a corporate environment.