VB scripting and Descriptive programming are two different sides of coin

Vb script is language used by QTP and we can do wrapper or substitute code using descriptive program over code written in QTP

e.g. If you would like to bypass object repository to do code. So, you can create your own description for repspective object. So, whenever script will playback. it will take mentioned object in the code

Below is the link for VB script

http://www.oreilly.com/catalog/vbscr...erpt/ch01.html