Chromebooks have been able to run Android apps for a while now, but there are still some limitations in how it works on Chrome OS. The biggest limitation is probably the lack of parallel tasking for apps, which means once you click away from an Android app on Chrome OS, the app pauses. It works just like it does on your phone, for the most part.
This “limitation” makes a ton of sense on phones; it keeps apps from draining resources in the background, and when you frequently keep multiple apps open it helps to make your phone run smoothly. On a laptop or desktop experience, however, it makes way less sense. Multitasking, especially in parallel, is the cornerstone of a desktop OS.
That’s why Google is finally bringing parallel tasks to Android apps within Chrome OS, which means you’ll be able to open multiple apps at once and have everything run simultaneously instead of pausing when you click over to another application. This brings Chrome OS much more in line with Mac OS and Windows, which is what 99% of users will be familiar with, anyways.
The feature will be going live in Chrome OS 64 and is currently up in the beta release. You can expect it to become official soon.
source: Chrome Unboxed