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