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Dialogs provide the user with a focused way of accomplishing, confirming, or viewing something without leaving a screen or page.
Alerts are urgent interruptions, requiring acknowledgement, that inform the user about a situation.
A confirmation dialog is short, simple dialog that ensures the user is performing an action intentionally. This is especially useful for dangerous or irreversible operations. Buttons with a higher priority function should be placed on the right side as shown here.
An actionless dialog may block user interaction for a period of time, usually until something finishes or some other event occurs.