Server OS

Server-oriented operating systems tend to have certain features in common that make them more suitable for the server environment, such as---

1-GUI not available or optional.
2-ability to reconfigure and update both hardware and software to some extent without restart,
3-advanced backup facilities to permit regular and frequent online backups of critical data,
4-transparent data transfer between different volumes or devices,
5-flexible and advanced networking capabilities,
6-automation capabilities such as daemons in UNIX and services in Windows, and

7-tight system security, with advanced user, resource, data, and memory protection.

Desktop OS

An operating system is software, consisting of programs and data, that runs on computers, manages computer hardware resources, and provides common services for execution of various application software. Operating system is the most important type of system software in a computer system. Without an operating system, a user cannot run an application program on their computer, unless the application program is self booting.

Examples of popular modern operating systems are: BSD, Linux, Mac OS X, Microsoft Windows and UNIX