designed for carrying loads over longer distances while remaining comfortable for the rider. These bikes are designed for bicycle touring over long distances carrying a lot of luggage
Ladies bikes are designed for women, insofar as they come in smaller frame sizes and a different frame geometry to that of a mens bike
Mountain bikes are designed to go on mountains or off-road trail riding, which means they're chunkier, have knobbly tyres on them, and a frame geometry which makes an MTB better suited for seriously uneven terrain
As the name suggests, road bikes are designed to ride on the road.But road bikes are optimised to make road cycling as efficient as possible, and because of that they'd perform terribly on a mountain dirt track