A server is a network computer that shares resources with and responds to requests from other computers on the network. Servers provide centralized access and storage of resources like applications, files, printers, and other hardware. When installing Windows Server 2012, there are three installation options: Server Core, Server with a GUI, and Minimal Server Interface. Server Core requires less disk space and has a smaller attack surface while Server with a GUI includes more graphical tools for management. The installation process involves inserting the installation media, selecting an installation option, and completing the setup process which reboots the server.