Answer Description
Google's Chrome OS is unique from other operating systems in that it primarily uses the web browser as it's user interface (Google Chrome). On some devices users can also install Android apps from the Google Play Store. It is not possible to run applications available for other operating systems like Windows and Mac on Chrome OS (unless they have a web version).
Wikipedia
Chrome OS (sometimes styled as chromeOS) is a Gentoo Linux-based operating system designed by Google It is derived from the free software Chromium OS and uses the Google Chrome web browser as its principal user interface Unlike Chromium OS, Chrome OS is proprietary software Google announced the project, based on Ubuntu, in July 2009, conceiving it as an operating system in which both applications and user data reside in the cloud: hence Chrome OS primarily runs web applications Source code and a public demo came that November The first Chrome OS laptop, known as a Chromebook, arrived in May 2011
Chrome_OS - Wikipedia, the free encyclopedia