From entry non-modal dialog in glossary Human Computer Interaction the Basics
A non-model dialog is a dialog box, like a small floating window, allowing the user to interact with it, or the rest of the application at will. This is particularly useful if the user may need to gather additional information to complete the dialog, where the dialog presents information the user may need to refer to, or where the user might need to repeatedly interact with the dialog. This is the opposte of a modal dialog.