User Operating System Interface

User Operating System Interface -CLI

Command Line Interface (CLI) or command interpreter allows direct command entry
Sometimes implemented in kernel, sometimes by systems program
Sometimes multiple flavors implemented –shells
Primarily fetches a command from user and executes it
Sometimes commands built-in, sometimes just names of programs

User Operating System Interface -GUI

User-friendly desktop metaphor interface
Usually mouse, keyboard, and monitor
Iconsrepresent files, programs, actions, etc
Various mouse buttons over objects in the interface cause various actions (provide information, options, execute function, open directory (known as a folder)
Invented at Xerox PARC

Many systems now include both CLI and GUI interfaces

Microsoft Windows is GUI with CLI ―command‖ shell
Apple Mac OS X as ―Aqua‖ GUI interface with UNIX kernel underneath and shells available
Solaris is CLI with optional GUI interfaces (Java Desktop, KDE)