How Will I Use an Operating System?

The user interface of an operating system is the portion of the program with which users interact.
The user interface can be

1. Command-line,
2.Menu-driven, and
3.Graphics-based.

A command-line interface requires a user to type the desired response at a prompt using a special command language.

To be an effective user of any command-line software, you must memorize its commands and their exact syntax-no easy task.

A menu-driven interface allows the user to select commands from a list (menu) using the keyboard or a pointing device such as a mouse.

A graphical user interface (GUI):

The trend is away from text-based, command-line interfaces to user-friendly, graphics-oriented environment called a graphical user interface (GUI).

Graphical user interfaces rely on graphics-based software.

Graphic-based software permits the integration of text with high-resolution graphic
image, called icons.

GUI users interact with the operating system and other software packages by using a pointing device and a keyboard to issue commands.

Rather than enter a command directly, the user chooses from options displayed on the screen.

The equivalent of a syntax-sensitive operating system command is entered by pointing to and choosing one or more options from menu or by pointing to and choosing a graphics image, called an icon.

Typically GUI includes some or all of the following parts:

-Icons, which are graphical images that represent items, such as files and directories.
-Agraphical pointer, which is controlled by a pointing device (mouse), to select icons and
commands and move on-screen items.
-On-screen pull-down menus that appear or disappear, controlled by the pointing device.
-Windows that enclose applications or objects on the screen.

GUIs have effectively eliminated the need for users to memorize and enter cumbersome commands.