multiprocessor and multicomputer

for improving the efficiency of the computer system.In multiprocessor environment , instructions can be executed parallely.

Multiprocessor systems have gained popularity over the years as they allow the user to do more than they could with a single processor system. Xbox 360, CELL, and Sequent are examples of multiprocessor systems.

Multiprocessor is pretty self-explanaatory. "Free" means the production build, as opposed to the development/debug version. Just looked this up myself.

The difference between distributed system and multiprocessor system is whether the processing units in the system share the main memory. If yes, then the system is multiprocessor system; otherwise, it's a distributed system.