They allow you to tell your computer what you want it to do. A dialog box appears as a shaded rectangle on your screen. Usually, you cannot access your document or any menu items until you complete the dialog. Dialog boxes request information in a variety of ways. They can include standard buttons, check boxes, radio buttons, text edit boxes, and navigational tools .
Standard buttons control the dialog box itself.
In a Print Dialog, it will be the Print Button. If you press your Enter key instead of clicking a button with your mouse, the default response will be assumed. Most dialog boxes also have a Cancel Button. Clicking on the Cancel Button closes the dialog without making any changes to your settings or document. Radio buttons and check boxes allow you to select several changes in a dialog box.