Well, crunching and folding are both DC projects (distributed computing) and are both based on a single principle. you get a WU (work unit) from the internet, and your machine processes it and sends the results back to the server, again on the internet and downloads the next WU. crunching is referred to S@H, Seti @ Home, which is a project searching for extraterrestrial life and Folding is a project which simulates the way that proteins in human body change and mutate (the process is called folding, hence the name), its believed that when a protein mis-folds in our body, that can lead to serious diseases like Cancer, Alzheimer's disease and Parkinson's. the idea of this is try and find out how exactly do these processes occur, and what exactly goes wrong and how to fix this, and find cures for all these currently pretty much untreatable diseases