An operating system is the software that sets the standards that computer programs use to communicate. It manages hardware resources, allows multiple applications to run concurrently and provides an interface for the user.
A modern OS includes a set of security features to prevent malware and viruses from damaging system files and data. It also abstracts lower-level details of hardware through application programming interfaces (APIs) that allow developers to focus on user functionality rather than the complex underlying computing architecture.
Multitasking
An OS arranges the execution of programs to make it appear that several things are happening at once, even though only one process can be run at a time. This requires the CPU to swap control between different processes thousands of times a second so that each can function for a reasonable amount of time without interference from other programs. In some systems, this is done using a cooperative model that depends on each program to give up its turn to other programs when asked.
It also handles input and output to peripheral devices, like printers and dial-up modems, recording device drivers in a standardized format that makes them easier to install and update. In addition, it may send messages to each application or interactive user and/or to a system administrator about the status of its operation.
The basic functions of an OS are the same for all major types, but additional functionalities have evolved to reflect changing computer hardware and user needs. For example, mobile OSes focus on seamless synchronization across different devices and platforms, while network OSes include cloud functionalities to support a growing range of Internet of Things (IoT) sensors and connected devices. Operating systems