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.
A computer network, or data network, is a digital telecommunications network which allows nodes to share resources. In computer networks, computing devices exchange data with each other using connections between nodes (data links.) These data links are established over cable media such as wires or optic cables, or wireless media such as WiFi.
Network computer devices that originate, route and terminate the data are called network nodes. Nodes can include hosts such as personal computers, phones, …