Which model describes a network where each user acts as both a client and a file server?

The model that describes a network where each user acts as both a client and a file server is the peer-to-peer model. In a peer-to-peer (P2P) network, all participants (or "peers") can share resources such as files without needing a central server. Each peer can request files from other peers while also providing access to its own files, allowing for decentralized file sharing. This flexibility enables users to both send and receive information directly, empowering all members of the network equally. Peer-to-peer networks are particularly useful for applications like file sharing, where users can contribute directly to the network's resources.

In contrast, the client/server model relies on dedicated servers providing resources or services to client devices, establishing a clear distinction between clients and servers. Token Ring involves a specific method of data transmission and does not inherently describe the roles of users as both clients and servers. Direct access refers to a storage method where users directly interact with the storage device, rather than dealing with user interactions in a networked environment. These distinctions highlight why peer-to-peer is the correct choice for the given question.