The term 'Road Bike' - or if you're old school "Racer" generally refers to a bike that can only be ridden on a road. Although with tyre widths available as wide as 28 and 32mm - riding on the rough stuff is now possible!
Road bikes tend to be constructed of either Aluminium or Carbon to make them light, though some steel framed road bikes are available.
Touring bikes are usually made from steel as these frames offer a much more comfortable ride. Steel is more compliant than aluminium. Aluminium is a little easier on the wallet.