-or, if you have a computer with more than one core- such as a dual core, quad etc, the apps can process the data (do things to it) using all of those cpus at once. So for eg, a quad core would have up to 8 threads available to an app. If I wanted to do something to the entire map, the multithreaded app would take the map and split it equally bwetween all of the cpus and they would all go at it at once. It's like having lots of computers!

monks