Computer operating systems are often described in terms of the methods by which they operate the computer. Some of these methods:
- Single user: it allows only one person to access and use the computer at one particular time. If another user need access to the computer system, he or she must wait until the current user finishes what he or she is doing.
- Multi-user: It allows two or more users to run programs at the same time. Some operating system permits hundreds or even thousands of concurrent users.
- Multiprocessing: It allows two or more processes to be executed simultaneously by separate CPUs that have access to a common main memory.
- Multiprogramming: it allows the execution of two or more programs concurrently by a single computer.
- Multithreading: it allows different parts of a single task to be executed at once.
- Embedded: it is designed to perform a specific task and does not allow the running of several programs, as it is the case with home computers.
- Multitasking: it allows two or more task to be executed simultaneously.
N.B; THE reverse of multitasking is Monotasking or single tasking system (only one task can be performed at a time).
