These applications run all the time on the server machine and they listen to specific ports, waiting for people or programs to attach to the port.
For the vast majority of people right now, the real e-mail system consists of two different servers running on a server machine.
The server machine finds the page you requested and sends it to you.
Each machine on the network can share resources and provide information to the others without being controlled by a central server machine.
The keyboard and mouse are connected to the server machine.
Each server machine runs multiple instances of the server process.
On the server machine, requests from the client are handled by a userspace program called .
In technical terms, each game server is actually a cluster of server machines.
But both have also moved into so-called client-server systems, in which computing is split between larger server machines and small clients.
The client's local operating system sends the message from the client machine to the server machine.