On what basis 'Exist()' method(in QTP) will identify existence of a test object in the open Application?

Question

On what basis does the Exist() method(in QTP) identify existence of a test object in the open Application?

Answer 1

QTP will try to match the description of the test object to a control in your application.

HP published a blog post about how QTP identifies objects which goes a bit into what Exist does and the (unexpected) side effect that you must not call Exist on a test object returned from ChildObjects.