See E. Rietman, Exploring Parallel Processing (1990); K. M. Chandy and S. Taylor, An Introduction to Parallel Programming (1992); D. I. Moldovon, Parallel Processing from Applications to Systems (1993); G. S. Almasi and A. Gottlieb, Highly Parallel Computing (1993).
The advantage of parallel processing is that it allows the brain to simultaneously identify different stimuli and allow for quick and decisive action.
This is one of the reasons that the human brain is much more powerful than the computer. While a computer is a million times faster than a human's neural network, it is the fact that we have a large number of processors compared to computers. As Donald Hoffman said (1998, p.xiii) "You can buy a chess machine that beats a master but can't yet buy a vision machine that beats a toddler's vision." The technology known as computer vision, however, allows computers to recognize objects visually.
Note that parallel processing differs from multitasking, in which a CPU provides the illusion of simultaneously executing instructions from multiple different programs by rapidly switching between them, or "interleaving" their instructions.
Parallel processing is also called parallel computing.In the quest of cheaper computing alternatives parallel processing provides a viable option.The idle time of processor cycles across network can be used effectively by sophisticated distributed computing software.