A server computer (often just called server) is a computer system that has
been designated for running a specific server application or applications. A
server computer that is designated for generally only one server application is
usually named for that application or purpose. For example, a server that runs
Apache HTTP Server software, or Microsoft's IIS is typically designated as a web
server, the computer running it is also simply called the web server. There can
be web servers, database servers, application servers, such as: email servers or
an Exchange Server, Share Point servers, Pre-press servers,
Network Video Servers, Domain Controllers, and Network Storage or Backup
Server. Server applications can be divided among application server computers
over an extreme range, depending upon the workload. Under light loading, every
server application can run concurrently on a single computer. Under heavy
loading, multiple dedicated servers may be required for each application. Under
medium loading, it is common to use one server computer (dedicated server) per
server application, in order to limit the amount of damage caused by failure of
any single server computer or security breach of any single server application.
Any server computer can also be used as a workstation, but it is typically not,
for support, maintenance, and risk management.
A server or server computer is also a designation for computer models
intended for use running server applications, often under heavy workloads,
unattended, for extended time. While any "workstation" computer can run server
operating systems and server applications, a server computer usually has special
features intended to make it more suitable, including more robust hardware and
fail-safe technology. Distinctions often include faster processor and memory,
more RAM, larger hard drives, higher reliability, redundant power supplies,
redundant hard drives (RAID),
compact size and shape,
PC tower chassis with
single or
dual processors, or modular design (e.g.,
blade servers often used in server farms),
rack or cabinet mounting, serial console redirection, etc. High capacity
storage servers are sometimes called
Terra Servers. Some servers are provided
bare-bones, others
built to order with numerous
accessories, and others come preconfigured with the server OS and
application software installed. Two very popular classes of servers are those
based upon the
Intel Xeon processor and the
AMD Opteron processors
The name server or server appliance also applies to network-connected
computer appliances or "appliance hardware" that provides specific services onto
the network. Though the appliance is a server computer, loaded with a
server operating system and a server application, the user need not
configure any of it. It is a black box that does a specific job. The simplest
servers are most often sold as appliances, for example switches, routers,
gateways, print servers, net modems, hardware spam filters, and firewalls.
A server is defined as a multi-user computer that provides a service (e.g.
database access, file transfer, remote access) or resources (e.g. file space)
over a network connection. Leading server or accessory manufacturers include:
Hewlett Packard (HP),
Systemax,
Visionman,
iStarUSA,
Cybertron,
Compucase, and others.
