The Network Information API allows developers to determine the connection types and the underlying connection technology that the user agent is using. In terms of web performance, this brings a whole new level to the way that we build web pages. Being able to reliably determine whether or not a user has a slow 2G connection or a speedy Wifi connection allows developers to serve content accordingly.

If you'd like to learn more about using the Network Information API together with service workers, I have written an article on my blog at deanhume.com