QuickTest Professional (QTP) Question:

The test object model is a large set of object types or classes that QuickTest uses to represent the objects in your application. Each test object class has a list of properties that can uniquely identify objects of that class and a set of relevant methods that QuickTest can record for it.

A test object is an object that QuickTest creates in the test or component to represent the actual object in your application. QuickTest stores information about the object that will help it identify and check the object during the run session.
A run-time object is the actual object in your Web site or application on which methods are performed during the run session.
When you perform an operation on your application while recording, QuickTest: