How Computer Servers Function
A server may refer to several different things. Simply a "server" is a software program that provides a specific service to client software running on the same computer. A "web server" stores data from websites and sends this data across the internet to users when requested. A "file server" is either software or hardware and software that are dedicated to storing data and making it accessible for users across a network. A "print server" is software or hardware dedicated to managing one or more printers. A "network server" manages all of the traffic on the network. A "database server" enables users to interact with a database. An "application server" runs the applications for users. A "name server" maps client and computer names to machine addresses. Generally speaking, however, a server is either hardware or software, usually on another computer system, that makes a network service available to and accessible by its clients.
The hardware that makes up a server varies from one server to the next, depending on the server's requirements. Most servers run on a network and, therefore, they do not require a monitor in order to function. Servers incorporate high-capacity hard drives for network storage, much larger computer fans, and uninterruptible power supplies to ensure there is no interruption if there is a power failure. Unlike home or user computers, servers utilize hardware redundancy - more than one piece of hardware, such as hard disks or power supplies, is installed so that in the event that one fails, another is available. In fact, most servers can be upgraded or maintained while they are running. Usually, it is not in the company's best interest to shut the server down. It is not uncommon for a server to stay on, without reboot, for months or even years.
The operating system on a server depends on the features that best suit the server environment. For example, some servers may require a graphic user interface, while others do not. In addition, some operating systems support the ability to reconfigure and update without restarting, while others do not. While Mac OS X offers server versions of its operating systems, it is rarely used as a server because of hardware and maintenance limitations and due to the fact that OS X does not support microprocessor architecture. Although the server editions of Windows do support microprocessor architecture, it is also not widely used as the operating system on a server. Instead, UNIX-like open source operating systems like Linux and FreeBSD are the dominant systems used on servers today.