A consistent theme between Qt Widgets and QML, the two GUI technologies Qt offers, is the use of the model/view architecture.
Simply put, the model/view architecture separates the data (model) from the display (view) of the data. This allows you to separate how the data is updated from how the UI designer presents the data. Should the UI designer change how the data is viewed, the code that puts the data in the model doesn't have to be changed.