Multicore processor is an new architecture design that place multiple processors on a single computer chip. Also known as Chip Multiprocessors.
The initial idea was to increase the processor's computing speed, anyhow by increasing the computing speed, in the same time, will require more power, and thus will increase the heat of the processor. This will effect the cost to cold down the system.
Instead of making it faster, the approach is to add in another processor to regain the higher processing speed. Here it comes to multicore revolution.