When you call a website, the request is sent through Tor, which means you pass several nodes before you land at your destination. Ensures that your whereabouts, etc. remain protected or in short: You are surfing anonymously.
After being able to play with Alpha and Beta since fall, the first stable version of the browser now lands in the Play Store. You no longer need an orbot, this is now included in the browser. Since the Tor Browser is based on Firefox, you will also find the same features plus the anonymization part.
Version 8.5 can now be downloaded from the Play Store.