A multiprocess system (also known as multitasking system) is one that executes many processes concurrently (simultaneously or in interleved fashion). In a uniprocess system, when the lone process executes a wait operation, the processor would sit idle and waste its time until the process comes out of the wait state. The objective of multiprocessing is to have a process running on the processor at all times, doing purposeful work.
(Sibsankar Haldar, Alex Alagarsamy. Operating Systems. Pearson Education India, 2010)