Answer Description
Only a domain will give you a centralized, controlled network and allow for file servers, print servers, and network shares. These are possible in a workgroup, but will not provide the network control that a business would require.
Wikipedia
A computer network is a group of computers that use a set of common communication protocols over digital interconnections for the purpose of sharing resources located on or provided by the network nodes The interconnections between nodes are formed from a broad spectrum of telecommunication network technologies, based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies The nodes of a computer network may be classified by many means as personal computers, servers, networking hardware, or general-purpose hosts They are identified by hostnames and network addresses Hostnames serve as memorable labels for the nodes, rarely changed after initial assignment
Computer network - Wikipedia, the free encyclopedia