Physics in games has grown rapidly over the last few years.
Characters are interacting with their virtual environments in many
ways that were impossible years ago. Take, for example, the new Tomb
Raider game. In the game, you can kick rocks and depending on which
angle you kick them and the incline, the rock will roll in that
direction relative to the force you applied. Also, tools and
projectiles respond based on laws contained in the physics engine.

The power of graphics cards is increasing rapidly. A powerful
graphics card could be the most expensive component in a machine. At
one point, I had very limited graphics cards. Then, 3dfx, the maker
of the Voodoo card, released the first 3d accelerator card. This card
worked together with the graphics card to provide 3d graphics.
Eventually the accelerator card was integrated into the graphics card.
Soon to be released is a physics card. Having a physics card will
allow your graphics card to move some processing over to this other
card which is dedicated to performing physics computations rapidly.
Games designed to take advantage of this card are still underway but
it should be a boom for gamers. In a few years, I will most likely
see graphics cards that license not only a graphics chip but also a
physics chip.

Also, here is some of the terminology you should know. You probably
already know that the chip in your computer that does most of the
computations is called the CPU (Central Processing Unit). The chip
that sits on your graphics card is called the GPU (Graphics Processing
Unit). The physics chip is called the PPU (Physics Processing Unit).