using object repository,qtp identifies object of an 
application

through object repository and obj identifier.
if it doesnt recognise we can use object spy or add obj in 
the repository manually.

QTP identifies the object in the Application by LogicalName 
and Class

  If any Qestions Plz Ask me......Prasad4urs@gmail.com

Qtp identifies objects with their logical name and physical
description.

In QTP we have object repository once we run application under
test(AUT).the objects are listed in the object repository
with there Logical Name and Physical Description.
One of the among two must be uniqe to identify objects
Ex:
if two person objects say ravi and ravi
logical name1=ravi description are age=21,sex=m,dob=1/3/86
logicalname2=ravi  description are age=22,sex=m.dob=2/12/86
actually object is identified by looking at there physical
descriptions if logical name is minimal