Just press the power and home buttons at the same time. Your screenshot will be stored in the Gallery app.
Firefox OS has a feature that lets you tell websites not to track your browsing behavior. Learn what tracking is, how the feature works and how to turn it on.
The Marketplace is a store that features apps designed for any device that runs Firefox OS, Firefox for Android or Firefox desktop.
This article covers the basic features of Firefox OS - apps, messaging, contacts, music and more. It also links to articles that you'll want to explore later.