What is a Bip file?

Hi,
I dont have 3DSMax so dont know, what is a bip file. How is it used for animations. I came to know about it when I asked a friend, if he could give me the boned animated model that he had gifted free, with bones animation. And he told that he had done animations with bip files and he does not knows how to convert into a bones animation file.

I would like to know the difference between a bip and bones animation, and is it possible to convert a bip animation into bones animation file, then that would be great.
Thanks in advance,
MSL.

As far as I know, *.bip-files can be importet into character-studio.
CS is an add-on for 3dsMAX that offers a fully jointed and customisable biped as a template for character animation.
You can scale each bone of this biped until it fits your model and import MotionCapture-Data to get it moving.
Since the CS-Biped is not made of standard-bones, I guess it won't be possible to convert and export the skeleton in a format that can be read by 3DGS.