By Stephen Bucaro
Server Racks Image from Wikimedia Commons
A server is a computer in a client/server network that provides services or "roles" on
a network and provides a central location for administration of the network. In order to
perform these roles, the computer has special server operating system software.
The role a server might play on the network is file server, print server, application
server, mail server, and many more. A server might perform a single role, or it might
perform multiple roles simultaneously.
One of the most common roles a server performs is file server. A file server
provides a pool of disc space allowing an organization to maintain a single copy files,
rather than multiple copies on different work stations. This has the advantage of the
requirement to backup only a single computer.
Another common role performed by a server is print server. A print server
allows workstations to share a single printer on the network, removing the need for
each workstation to have its own printer.
When a server acts as an application server it allows an application used
by multiple workstations to be run on the server. This has the advantage of requiring
only one instance of the application to be patched and updated.
As a mail server, the server stores and transfers email between different
computers on the network.
Some of the most important roles performed by a server is domain controller,
Domain Name System (DNS) server, and Dynamic Host Configuration Protocol (DHCP)
server. A domain is a network or subnetwork where the group of clients and servers
on the network or subnetwork use a central security database stored on a centralized
server known as a domain controller to authenticate users. This simplifies user
logon servers and services and allows centralized administration.
The DNS service resolves domain names to IP addresses. If resources on the network
are to made available on the Internet, you would need a server configured a DNS server.
DHCP automatically assigns IP addresses on client computers. With DHCP a device
can have a different IP address every time it connects to the network. In most configurations,
a devices IP address will expire after a pre-configured interval and the device's IP address
will change while it is still connected.
Another role performed by a server is Web server. A Web server runs Web server
software which allows the creation of websites, and uses HTTP protocol to respond to
requests from a user's browser by sending back Web pages and uses FTP to allow file
downloads and uploads.
Administration of a server involves keeping the antivirus software up to date,
performing a routine regimen, and installing software updates and patches.