The HTML <dialog> element represents a dialog box or other interactive component, such as an inspector or window. <form> elements can be integrated within a dialog by specifying them with the attribute method="dialog". When such a form is submitted, the dialog is closed with a returnValue attribute set to the value of the submit button used.
The HTML <menu> element represents a group of commands that a user can perform or activate. This includes both list menus, which might appear across the top of a screen, as well as context menus, such as those that might appear underneath a button after it has been clicked.