Most computers only have one processor and scheduling is therefore a high priority.
Processor scheduling divides a computer processor's work between multiple programs so that it is continually switching from one open application to another. This gives the appearance that the computer is running a number of different programs simultaneously.
Function
The operating system of a computer sends instructions to the processor. These instructions are called "processes." Each process is made up of "threads." A thread is the smallest task a processor can perform. The operating system schedules the amount of time that a given thread will run before it tells the processor to switch to a thread related to another program.
Options
It is sometimes possible to change the way an operating system handles scheduling. For example, Windows XP users can choose either "programs" or "background services." The first option maximizes the time the processor spends on the current program, while the second devotes equal processor resources to all software, explains TechRepublic.
Parallel Processing
Some computers have more than one processor. Each processor can handle a minimum of one thread at a time. On these systems, the scheduler can speed up the execution of software instructions by having the processor run multiple threads "in parallel," which means simultaneously.
