To create Programs the User simply drags and drops "Blocks" into the workspace which can then be translated into Python/Glowscript Code.
Utilizing VPython/Glowscripts access to WebGL means Users can see actual renders of Physic Concepts. Visual Feedback of the the Users current program State allows for better understanding of concepts and easier problem solving.
The Blocks themselves offer realtime feedback to the User, allowing them to better understand how they are affecting each variable (and Physical Object) and what "attributes" they have the ability to change.