what is the difference between ChromeOS and Android？

 first of all similarities

Both are designed by Google

Both are Linux-kernel based operating systems.

Difference

Chrome OS is a linux kernel based operating system and uses Google Chrome web browser as the user interface.

Android is a mobile operating system and is a modified version of linux kernel based

It is free and open source software. It is developed by a consortium of developers known as the Open Handset Alliance and commercially sponsored by Google.

While android is mainly catered for smartphone and tablets, Chrome os is mainly for netbooks and other light weight computers.

Android and Chrome OS may converge one day, but for now Chrome OS major focus is on netbooks(Chromebook)

Android is basically the OS that runs on a cell phone. It wasn't meant to be installed or used on a tablet, but once it was tested it was a winner, and has stuck ever since. Now Chrome OS is the Android version of an OS meant to be run on a laptop as a lightweight OS, similar to HP'S WebOS that never took off.

Many developers have managed to get the Android OS running on many varied laptop and desktop computers with great success, and sometimes not so much. It'sa great way to breathing new life into an older machine, as well as gives you a great support tool when helping people with their devices. Also, it helps to keep many machines out of the landfills. Remix was a fully desktop version OS of Android, but that has collapsed and almost died off. There are still plenty of online sources of Remix, and the various versions of the Android OS you can try to install onto your own equipment, but the push now seems to be for the Chrome OS to become a better standard for many out there. Now if the device it's installed on also runs an Intel CPU, and has support for the Google Play store, then with various apps out there your device can now even install and run many Windows apps. Seems like the old days all over again from the 80s and 90s computer era,but that's another story altogether.

Currently, you can install android apps on Chromebooks and Chrome OS devices.

Read:Which is the Best Way to Use Multiple Accounts on Android