What are profiles?
From Web3D.org
Profiles are subsets of the x3d specs. They are declared in the x3d tag, like this:
Code: <X3D version='3.1' profile='Interactive' ...
When you decide to create a scene, you should choose a profile that contains the nodes and functionality you need. It acts as a contract to the viewer (browser) which should protest if it is not capable of supporting that profile.
Current profiles are:
Core Full Immersive Interactive Interchange MPEG-4 interactive