THE USER INTERFACE
1. Graphical User Interfaces (GUIs)
•Most modern operating systems, like Windows and
the Macintosh OS, provide a graphical user interface
•A GUI lets youcontrol the system by using a mouse
to click graphical objects on screen.
•A GUI is based on the desktop metaphor. Graphical
objects appear on a background (the desktop),
representing resources you can use.
2. GUI Tools
• Icons are pictures that represent computer
resources, such as printers, documents, and
• You double-click an icon to choose (activate) it, for
instance, to launch a program.
• The Windows operating system ofers two unique
tools, caled the taskbar and Start buton. These
help you run and manage programs.
3. -Applications and the Interface
• Applications designed to run under one operating
system usesimilarinterface elements.
• Under an OS such as Windows, you see a familiar
interface no mater what programs you use.
• In a GUI, each program opens and runs in a separate
window—a frame that presents the program and its
• In a GUI, you can run multiple programs at once,
each in a separate window. The application in use is
said to be the active window.
•GUI-based programs let you isue commands by
choosing them from menus.
•A menu groups related commands. For example, the
File menu’s commands let you open, save, and print
•Menus let you avoid memorizing and typing
•In programs designed for the same GUI, menus and
commands are similar from one program to another.
5. -Dialog Boxes
•A dialog box is a special window that appears when
a programor the OS needs more information
before completing a task.
•Dialog boxes are so named because they conduct a
“dialog” with the user, asking the user to provide
more information ormake choices.
6. -Command-Line Interfaces
• Some older operating systems, such as DOS and
UNIX, use command-line interfaces.
• In a command-line interface,you type commands at a
• Under command-line interfaces, individual
applications do not need to look or function the same
way, so diferent programs can look very diferent