The binding extender is a central piece of live binding model. It is represented by the BindingExtender component; this component must be present on the component tray (of your form or window) in order to enable it for live binding.

The main purpose of the binding extender is to keep track of bindings defined on each control in the container (form), and provide extender properties to them.

The binding extender is generic; it does not have a specific knowledge about types of bindings that can be used. The available binding types are defined on the binding extender by a binder (or binders) that register with it. For explanation of binders, see further below.