Chrome OS is an operating system developed by Google, it is designed to be a fast and lightweight operating system that is based on the Google Chrome browser, it uses the Linux kernel. Chrome OS runs mainly on web applications, although it does support native applications as well.
Currently, the latest stable version of Chrome OS is version 73.0.
Chrome OS is mainly found on Chromebooks, laptops that run Chrome OS. They are also shipped on Chromeboxes, Chromebases and Chromebits. The open-source equivalent of Chrome OS, known as Chromium OS, can be compiled to run on computers other than the ones with Chrome OS pre-installed.
Chrome OS has 4 release channels, Stable, Beta, Dev and Canary.
The stable channel of Chrome OS releases builds that have been fully tested and has minimal bugs, it gets minor updates every 2-3 weeks and major updates every 6 weeks.
The beta channel builds have not been tested fully, so they are more prone to bugs, it gets minor updates every week, and major updates every 6 weeks.
The dev channel is very unstable, it has been tested very little and is usually a lot buggier than the beta channel. It gets updated once or twice a week.
The canary channel is bleeding-edge, it has not been tested at all. It is updated daily.
These screenshots are from Chrome OS 69.0.3497.35