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 set of computers sharing resources located on or provided by network nodes The computers use common communication protocols over digital interconnections to communicate with each other These interconnections are made up 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 include personal computers, servers, networking hardware, or other specialised or general-purpose hosts They are identified by network addresses, and may have hostnames Hostnames serve as memorable labels for the nodes, rarely changed after initial assignment
Computer network - Wikipedia, the free encyclopedia