As the name implies, a dialog box serves to initiate a dialog with the user. It is a window that pops up on the screen with options that the user can select. After the selections have been made, the user can typically click "OK" to enter the changes or "Cancel" to discard the selections. It is customary for menu options that include an ellipsis at the end, such as "Preferences..." or "Save As...", to open a dialog box when selected.
For example, if a user selects "Internet Options..." from the Options menu in Internet Explorer, a dialog box will pop up allowing the user to choose the default home page, change the security settings, empty the browser cache, and modify several other settings. Once the selections have been made, the user can click "OK" to use the new settings, or "Cancel" to discard the changes. Some Windows programs also have an "Apply" option that activates the selections without closing the dialog box.
When a user selects "Open..." from the File menu, an "Open dialog box" appears, allowing the user to browse the hard drive and other disks for files to open. When "Save As..." is chosen from the File menu, a "Close dialog box" pops up, allowing the user to type the name of the file and choose where to save it. While dialog boxes may not seem too exciting, they provide an intuitive way to communicate with the computer and are an essential part of today's computer interfaces.