Definition of AD

A piece of content to be delivered by Commerce Server based on a specific formula for delivery referred to as Need of Delivery (NOD).

A boundary that the common language runtime establishes around objects created within the same application scope (that is, anywhere along the sequence of object activations beginning with the application entry point). Application domains help isolate objects created in one application from those created in other applications so that run-time behavior is predictable. Multiple application domains can exist in a single process.