This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
"Multiprocessing" isn't really a term with a precise meaning in this context; but on most operating systems the definition of a process is running code with its own address space, and a thread shares its address space with other threads; generally a process can contain one or more threads. Therefore "multiprocessing in Java" would imply starting multiple separate processes -- i.e., multiple separate JVMs. If one JVM wanted to start another, it would use the Runtime.exec() family of methods.