Solution:
Peer-to-peer
Explanation
Access to shared resources are controlled separately on each computer in the workgroup or peer-to-peer models. For example, each computer in a peer-to-peer network maintains its own set of user accounts.
A domain is a collection of computers that share a common security database. Access is controlled by maintaining access control lists in a centralized directory. The client/server model places shared resources on a server. Resources are accessed by clients.
Hope this might help you.