Preemptive Multitasking

One of the most distinguishing features of Linux-ish systems is preemptive multitasking. This is the means by which the kernel scheduler may suspend a process and continue the execution of another. This gives the impression of simultaneous execution of programs. Other operating systems (e.g., MacOS, Windows) use cooperative multitasking. Under this scheme, a process may allow other processes to run. Those processes may run for indeterminate periods of time before returning control.