The following is a quote from Team Hack a Day.

" Folding@home is a distributed computing project designed to perform computationally intensive simulations of protein folding. The project's goal is to add greater understanding to protein folding, misfolding, aggregation, and related diseases. Such diseases include BSE (mad cow), Creutzfeldt-Jakob disease, Alzheimer’s, Parkinson’s, among others.

Folding@home does not rely on powerful supercomputers for its processing; instead, the primary contributors to the Folding@home project are many thousands of personal computer users who have installed a small client program. The client runs in the background, and makes use of the CPU when it is not busy. In most modern personal computers, the CPU is rarely used to its full capacity at all times; the Folding@home client takes advantage of this unused processing power.

The Folding@home client periodically connects to a server to retrieve work units. These are packets of data upon which to perform calculations. Each completed work unit is then sent back to the server."

For more info goto : http://www.teamhackaday.com/forum/viewtopic.php?t=666&sid=857287bbb82e87e969e746ab94da6b83