Descriptive programming is an advanced concept in QTP.We can
handle the application without using object repository.It 
can be implimented by using object syp when the application 
is available.And It can also be implemented with out 
application in hand based on the properties of the object( 
which can be done by experts).The main purpose of using DP 
is it increases the performance of the tool.Easy to 
maintain.Very flexible in objectsvimplementing and we can 
modify the script easily when compare to QTP script/code.