by following Mark's suggestion, and selecting the titles of “Using Programmatic Descriptions' and
'Using Description Objects for Programmatic Descriptions' we can get the ideas, even though there is no formal definition of it.
BTW ... the reason I posted this question originally is because some clients asked me, and I was not quite sure how to answer it correctly.
Chin8673, I dont know about a formal description but the basic idea of programmatic description is to make object identification independent of pre-stored identification properties in the OR. Therefore programmatic description helps you identify and work with objects in your application on the fly, without having them stored in the OR. As the name suggests, you are 'describing' the object to be identified or worked on using programming statements and syntax.