A game server is used by clients or gamers to run multiplayer computer games over the Internet. The servers are hosted either locally or remotely. Those hosted locally can be accessed by those in the local Intranet, and those hosted remotely can be accessed from across the world. Computer and video games playable on game servers often require membership fees in return for access.
A game server can be defined in three ways: as a computer program used to serve the requests of clients, as a computer that hosts such programs, or as a software/hardware system used for databases, files and mail. All three definitions tend to be interdependent on one another. A game server will be both the physical computer used to host the program and the program itself.
Server hardware differs from normal computers in many ways. The server can save critical space by not having a graphics interface, or monitor, or by omitting audio and USB interfaces and capabilities. Servers often need to run continuously without being shut off, they need to be fault tolerant and, most importantly, they need to be backed up. Operating systems (OS) used by servers tend to be simple compared to operating systems used by computers, because they are required to do fewer tasks.
A person may locally host such a server, if he wishes. These tend to be called listen servers, rather than dedicated servers, because the host is able to participate in the game with his clients. This is usually run on a local area network (LAN) basis, meaning the connection to the server can easily be cut and will be if, for example, the host stops playing. The server is also placed under extra strain, because both the host and the users are playing the game. These servers tend to have a lower number of users.
A dedicated server is more expensive and tends to be remotely hosted by the game provider. It is run independently of any of the gamers, or clients. This means the server is better able to provide a game platform for hundreds, if not thousands, of gamers. The capacity for users depends on the size of the server and the number of dedicated servers linked to any one multiplayer game.
A third, growing option is for a game server to move from a listen or dedicated server format, both of which require the individual host or host company to physically buy the hardware and the software, to cloud computing and cloud servers. In cloud computing, a company runs a large number of servers and other companies rent server space to run their websites and services. Game companies, especially start-ups, may opt to hire a company to control its dedicated servers from a distance while they concentrate on the game itself.