Knowledge is Power

Microsoft Windows Server OS (operating system) is a series of enterprise-class server operating systems designed to share services with multiple users and provide extensive administrative control of data storage, applications and corporate networks.
On the other words, Windows Server is a group of operating systems designed by Microsoft that supports enterprise-level management, data storage, applications, and communications. Previous versions of Windows Server have focused on stability, security, networking, and various improvements to the file system.

Development for Windows Server started in the early 1980s when Microsoft produced two operating system lines: MS-DOS and Windows NT. Microsoft engineer David Cutler developed the kernel of Windows NT with the intent to provide speed, security and reliability that large organizations require in a server operating system.
Prior to the release of Windows NT, many companies relied on the Unix operating system that required expensive RISC-based hardware to run file and printing services. Windows NT had the ability to run on less costly x86 machines.
A key feature in the NT architecture is symmetric multiprocessing, which makes applications run faster on machines with several processors.
Later iterations of Windows Server can be deployed either on hardware in an organization's data center or in a cloud environment, such as Microsoft Azure. Key features in later versions of Windows Server include Active Directory, which automates the management of user data, security and distributed resources, and enables interoperation with other directories; and Server Manager, which is a utility to administer server roles and make configuration changes to local or remote machines.

History of Windows Server

1994: Windows NT 3.5 Server
1995: Windows NT Server 3.51
1996: Windows NT Server 4.0
2000: Windows 2000
2003: Windows Server 2003
2005: Windows Server 2003 R2
2008: Windows Server 2008
2009: Windows Server 2008 R2
2012: Windows Server 2012
2013: Windows Server 2012 R2
2016: Windows Server 2016