A server is a computer or software system that provides data, resources, or services to other computers (clients) over a network. The term is used at multiple levels of abstraction: it can refer to the physical machine, the operating system instance (host) running on that machine, a specific service process running on that host, or an application that provides some capability to clients. Context usually makes clear which level is meant.
In practice, a single physical server often runs many services simultaneously — each logically separate but sharing the same hardware and OS.
In This Home
The lab servers are Raspberry Pi CM5 boards running Linux. Each physical machine is a server in the hardware sense; each Linux OS instance is a host; each Docker container is a service. See [Home Network](30-Systems/Home Network/index.md) for the full picture.