Orweb is a companion browser to https://f-droid.org/packages/org.torproject.android, the port of Tor to
Android.
Orbot anonymizes internet traffic by routing it through many different stages
and you must have that enabled first, though root isn't needed. Orweb disables
certain other browser features that could be used to identify you.
Please note that Orweb is superseded by https://f-droid.org/packages/info.guardianproject.orfox,
available from the
Guardian Project
repo. Orweb is no longer maintained at all.