Final answer:
A server is the computer that hosts a network operating system, providing services within a network. Operating systems evolved from proprietary systems to the UNIX system, which also eventually became commercialized.
Step-by-step explanation:
The computer that host a network operating system and provides services to other computers in the network is called a server. This term outlines how computer networking operates with dedicated machines managing resources and offering a wide array of functions to client computers. In the history of computing, there have been notable developments in operating systems, starting from proprietary systems created by companies such as IBM, Microsoft, and Sun Microsystems, to the advent of UNIX which eventually became commercial through companies like Novell and SCO.