When you point to the control, you'll see a green binding icon in the upper-right corner that shows you what the control is bound to. In this case, a Repeating Section control is bound to the Customer group, and the green icon confirms that it's bound correctly.
The main advantage of basing a form on an XML schema is that data entered into the form is saved in files that share their data structure with other files governed by that schema. This makes the data easy to share and reuse. But just how does the data go from the form into the data structure? By binding.
Binding links a form control automatically to the field or group that corresponds to a schema data element. This sounds rigorous, and it should be, but it's also easy: By dragging the field or group onto the form, then picking a control, you bind the control to the field or group. Sure beats hand filing.
As the picture shows, a green binding icon appears when you point to the control, showing you what the control is bound to. If there's something wrong with the binding, you'll see a different kind of icon (you'll get examples of this in a later practice session).