Описание тега data-binding

Data binding is a general technique that binds two data/information sources together and maintains them in sync. This is usually done with two data/information sources with different types as in xml data binding. However, in UI data binding, data and information objects of the same type are bound together (e.g. java objects to Java UI elements).

If the binding has been made in the proper manner, then, each data change is reflected automatically by the elements that are bound to the data. The term data binding is also used in case where an outer representation of data in an element changes, and the underlying data is automatically updated to reflect this change. As an example, a change in a TextBox element could modify the underlying data value.

Ref:

WPF DataBinding: Windows Presentation Foundation ( wpf) data binding provides a simple and consistent way for applications to present and interact with data. Elements can be bound to data from a variety of data sources in the form of common language runtime ( clr) objects and XML.