Stable is what regular users know as Google Chrome, the one we use normally. Google releases updates through 4 channels: Stable, Beta, Dev, and Canary. How do Google browser versions work exactly? This Alpha version of the Google browser does not install itself over the previous version, and is perfect for testing. Google Canary is really the cutting-edge version of a Google Browser, which means that even before the updates have been released on Google Chrome, developers can test them on the Canary.
