Modals vs non-modals

When modal dialogs pop up, they require user interaction before users can continue using the rest of the application. In other words, they block interaction with the rest of the application until the dialog is dismissed.

Non-modal dialogs (also called modeless), on the other hand, do not block interaction with the rest of the application. They can easily be ignored or minimized by users and do not cause any disruption to their tasks.