An emulator is a dev tool that recreates the whole OS. It is very useful for devs since that way you can test your app on multiple architectures or Android ve

An emulator is a dev tool that recreates the whole OS. It is very useful for devs since that way you can test your app on multiple architectures or Android versions. You can even use it to run automatic tests after each commits (or each day) in order to control your app quality. On the other hand, what we have in ChromeOS (and soon Chrome) is a reproduction of the Dalvik/ART runtime. As a runtime, its only job is to allow Android apps to run. It probably was an huge amount of work for the Chrome team (apparently, they have been working on it for quite some time but now that it is here, it means that with it installed you can run Android apps on your desktop computer. so, it is both a matter of features, speed and convenience. I am an Android dev. In the startup I work for, we have mobile apps (Android, iOS and even Windows Phone), a website and are even working on desktop versions of our product. I don't know what this will mean for us though. Sure, we can use this new runtime to make our Android app run on the desktop but it has been thought out for mobile UX so a huge amount of work would be necessary to make it work nicely with the mouse+keyboard combo. It is very nice that we now have that option though, especially with Material Design looming in the corner.