A bicycle trailer is a motorless wheeled frame with a hitch system used to transport cargo by bicycle. The design of the trailer is based on its intended use. There are trailers designed specifically to carry children and pets, to carry cargo and to facilitate bicycle commuting.
Trailers designed to carry cargo by bike are as diverse as there are things to carry- the following are just some examples.
BOB Yak Bicycle Cargo Trailer
Kamp-Rite Midget Bushtrekka Bicycle Camper Trailer