Along with the stable version of Chrome Browser, there are tons of other distribution channels that let you try out the newest versions before anyone else. Chrome Beta is the first step before fully launching a new version, offering unique features that only arrive to later versions when they arrive for mass distribution among all users.
While this version of Chrome Dev is usually at least two versions ahead of the stable channel (as indicated by its serial number) Beta is just a step before them which is why it's already stable enough even for use as a main browser tool. Notwithstanding, its main objective is to work as a trial zone for users to send feedback directly to developers.
The best thing about Chrome Beta is that it works side-by-side with the completely stable version of the well known browser, without interfering at all and with each running independently. Ultimately, Chrome Beta is another awesome way to enjoy the latest improvements on Google's browser in a controlled and safe way.