1) An enterprise server is a computer containing programs that collectively serve the needs of an enterprise rather than a single user, department, or specialized application. Historically, mainframe -sized computers have been enterprise servers although they were not referred to as server s until recently. As smaller, usually UNIX -based servers and Wintel computers have become faster and have been provided with enterprise-wide program management capabilities, they also been referred to as enterprise servers. In this usage, an enterprise server is both the computer hardware and its main software, the operating system. Examples are Sun Microsystems' computers with their UNIX -based Solaris or Linux systems, Hewlett-Packard ( HP ) systems, the upper end of Windows 2000 systems, and IBM's iSeries systems (the largest of which is the zSeries 900 -formerly called the S/390 ).
2) Some companies use enterprise server to describe a "superprogram" that runs under the operating system in a computer and provides services for the system administrator and for the business application program s and more specialized server s that run in the computer. Before this usage originated, such services were sometimes considered part of the operating system itself or came in separate software packages. Originally, many services provided by an enterprise server tended to be available only on IBM or similar mainframe computers while less powerful computers ran specialized applications. As these smaller "server" computers (such as those from Sun Microsystems and H-P) became better adapted for business (and recently Internet) applications, the bundle of services required to manage a company-wide set of applications was renamed "the enterprise server." More specialized servers include the Web server , firewall server, database server, and so forth.