What type of router device sends client requests to the first available server in a server farm

A server farm is a group of computers connected together. There can by thousands of them in single farm. They are used to accomplish tasks or problems which can not be processed by a single personal computer.

Client-server technology is not industry specific; any company that would benefit from a client-server network would use it. Further to the point, any company that uses email uses a client-server technology. We can therefore say that client server technology has become ubiquitous, and can not be attributed to any particular industry or segment.

Mid- tier server

it explains that server virtualization is the separation of server computing functions ... Server virtualization technology allows for dynamic and automatic creation, ... full virtualization and paravirtualization along with hardware acceleration logic.