Beer tankard

I was garage sale shoping I came across what I though was a beer mug.i was then told it was a tankard?? So my question is what would u call this a beer stein or a tankard.and my second question is it a rare peice?? What kind of value is something like this worth? It stands from top to bottom 20 inches the lid is removable it is not attached to mug.it has not chips. Its in very good conditio..if anyone out there can help me out with some info on this I would highly appreciate it.thank u for your time DAVIDSERNA