What is operating system
An operating system is a program that manages the computer hardware. It also provides a basis for application programs and acts as an intermediary between the computer user and the computer hardware.A good operating system can be extremely complicated and can support complex tasks and applications in computers.
One side a well designed operating system always has the ability to multiprogram. In a non-multiprogrammed system,jobs gotta wait for some task,such as an I/O operation,to complete.But in an multiprogrammed system,the operating system simply switches to and executes another job.When that job needs to wait, the CPU is switched to another job,and so on.
The other side a good OS are interrupt driven.If there are no processes to execute, no I/O devices to service and no users to whom to respond,an operating system will sit quietly, waiting for something to happen.Except this ,a strong safety system is very significant.Without protection against errors, either the computer must execute only one process at a time or all output must be suspect . An properly designed operating system must ensure that an incorrect program cannot cause other programs to execute incorrectly.
Here is a introduction of some popular OS around the world:
Windows: the Microsoft Windows operating system is a set of operating systems developed by Microsoft Corporation of the United States. It was introduced in 1985. It was originally a Microsoft-DOS emulation environment. The subsequent system version was not only easy to use due to continuous update and upgrade by Microsoft,but also slowly became the favorite operating system for every household.
Linux: Linux is a free-to-use and freely distributed Unix-like operating system. It is a multi-user, multi-CPU based operating system based on POSIX and Unix, It runs major Unix tools, applications and network protocols. It supports both 32-bit and 64-bit hardware. Linux inherits Unix's network-centric design philosophy and is a stable multi-user network operating system.
