DataBinding
SAPUI5 uses data binding to bind two data sources or information sources together to keep them in sync: All changes in one source are also reflected in the other one.
For data binding, you need a model and a binding instance: The model instance holds the data and provides methods to set the data or to retrieve the data from a server. It also provides a method for creating bindings to the data. When this method is called, a binding instance is created, which contains the binding information and provides an event, which is fired whenever the bound data changes. An element can listen to this event and update its visualization according to the new data.
The UI uses data binding to bind controls to the model which holds the application data, so that the controls are updated automatically whenever application data changes. Data binding is also used the other way round, when changes in the control cause updates in the underlying application data, for example data entered by the user. This is called two-way binding.