§ The primary goal of an Operating System is to provide an interface.
§ Such an Interface helps in using the computer conveniently.
§ It allows the user to easily access and communicates with the software and the hardware.
§ The user can interact with the computer by using mainly two kinds of interfaces provided by the operating system. They are: Character User Interface and Graphical User Interface
Graphical User Interface Operating System:
§ Graphical User Interface (GUI) operating system presents commands in graphical form.
§ For example, application programs, commands, disk drives, files etc. are presented in the form of icons.
§ Usually a command is given to the computer by clicking with mouse on the icon.
§ GUI also provides menus, buttons and other graphical objects to the user to perform different tasks. GUI is very easy to interact with the computer.
§ Examples of GUI operating systems are Windows, Linux, and Solaris.
§ Today Windows is commonly used in PCs. In Windows, mouse is used as input device.
§ Interfacing: It provides commands in graphical form on the computer screen. The user gives commands to computer by checking with mouse on the icon. The users have not to memorize commands. Usually mouse is used for interfacing with computer.
§ Control: Although a GUI offers a better control of a file system and computer resources but often users have to use command line to complete a specific tasks.
§ Ease: It is easy to learn and use.
§ Multitasking: GUI provides facility to open multiple programs each in a separate window. So it enables a user to view, and to manipulate multiple things at a time on computer screen.
§ Speed: A GUI is easier to use. However, it is slower to perform different tasks.
§ Scripting: Although a GUI enables a user to create shortcuts, or other similar actions to complete a task. However, GUI does not provide the facility of scripting a sequence of commands to perform a task.
Command Line Operating System:
§ A command line operating system provides a command prompt on the computer screen.
§ The commands are given to the computer by typing on the keyboard.
§ The commands are typed according to the predefined format.
§ The users have to memorize commands and rules of writing these commands.
§ It is not an easy way to interface with the computer.
§ Examples of Command line operating systems are DOS (Disk Operating System), and Unix etc.
§ Interfacing: It provides commands prompt on the computer screen. The user gives commands to computer by typing on the keyboard. The users have to memorize commands and rules of writing these commands. Usually keyboard is used for interfacing with computer.
§ Control: It provides full access to computer resources.
§ Ease: It is difficult to learn and use.
§ Multitasking: Although many command line operating systems allow multitasking, but it is difficult in these operating systems to view multiple things at a time on computer screen.
§ Speed: The command line interface is faster than GUI to perform different tasks.
§ Scripting: A command line interface enables a user to easily script a sequence of commands to perform tasks.