Data binding is an essential concept to software development, and one that is luckily made near-trivial by Visual Studio.
In a one-way binding, data is populated in one direction, to the end UI control. In this system, changing a value in the control does not reflect in the data source.
In a two-way binding scenario, data can flow back from the control to the data source. This is useful for an 'edit' role, versus a 'label' role which would more appropriately make use of one-way binding.
Data binding was made popular in WinForms (.NET 2.0), and Visual Studio 2012 makes it intuitive. Through multiple methods, such as Binding.Source and DataContext switching, a control can be bound to a source in just a few clicks.
In this video, I will show you how to bind a TextBlock to the DisplayName property in a file chosen from a FilePicker.
XAML File Pickers - http://msdn.microsoft.com/en-us/library/windows/apps/jj655411.aspx