Multitasking lets your computer do more than one thing at once, like duplicating a file in the background while you write a document. Windoze NT and Windoze 95 can pretend to multitask with preemptive multitasking. This is where each process gets a certain amount of processing time. MacOS does a better job of multitasking than Windoze, but doesn't do as well as UNIX and OS/2 (until OS X.)