DataControl/BindingContext/BindingContainer

Data Control/DataControls.dcx:

A data control is essentially a bridge that makes data from a source available to the user interface in an ADF Fusion Web Application. You can use the objects in the data control to create databound user interface components, but not directly.

It identifies the Oracle ADF model layer data control classes(factory classes) that facilitate the interaction between the client and the available business service.

This type of data control is generated by JDeveloper when you create an application module in your ADF Business Components application.

Typically, there is one data control for a given source (bean, EJB, or URL). However, you may have additional data controls that were created for other types of objects (for example, application modules or web services).

Note:-

DataControl.dcx is registry of DataControls.
DataControl.dcx  is not created for ADF Business Componets.
This File is created when tou register Datacontrol on technologies  other than ADFBC

BindingContext/ DataBindings.cpx :

Binding context is a runtime map between the data controls and page definition of pages in the application which is used to access the binding layer. It is accessible through the EL expression in your jspx pages.
At runtime, the interaction with the business services initiated from the client or controller is managed by the application through a single object known as the Oracle ADF model binding context. 

Note:
DataBindings.cpx is registry of Page definition files 
It is a metadata file contains ADF Binding Context for the entire Application.



Binding container/Page Definition: 

It  is a request-scoped map that is used to instantiate the page bindings. This is accessible through the EL expressions. Also, since it is request-scoped map, it is accessible during every page request.

Each JSF page has its own Page Definition  and it contains Bindings, Executables(Iterators) and Datacontrol mapping.
Note: Where Iterators are used to access the Binding Context of that particular page.