Sync is not a new feature but something that have been implemented on modern browsers for some time, the idea is to make portable all your personal information. The main advantage is you get all your favorites, passwords, cookies, visited urls, searches, extensions, etc with just one click. The desadvantage is you sacrifice your privacy and big companies like Google has access to this information and they can do whatever they want.
To use Sync just look for it on the upper right corner of the browser, login, give it a name and done. Your personal information will be available in the browser.
Download Brave:
http://bit.ly/_brave_browser