<br> [MAS.865](../../index.html) > [Programming](../index.html) > Operating Systems ##RTOS An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs.<br> The components of an operating system all exist in order to make the different parts of a computer work together. All user software needs to go through the operating system in order to use any of the hardware, whether it be as simple as a mouse or keyboard or as complex as an Internet component.<br> <p align="center"> <img src="kernel.svg" width="20%" height="20%"> <br> Diagram </p> Real-Time Operating System (RTOS) is an operating system intended to serve real-time applications that process data as it comes in. It is measured by its consistent fast response to tasks. <br> <ul> <li>Time sharing => switch between tasks based on clock interrupts</li> <li>Event-driven => switch between tasks based on their priorities</li> </ul> [freeRTOS](https://www.freertos.org/) [QP-nano](https://www.state-machine.com/)