Many people ask me the difference between dump trucks and dump trailers.
A dump trailer has a detacheable trailer that is completely separate from the truck that pulls it.
Dump trailers come in many different sizes and can be pulled by anything from a pickup truck all the way up to a semi.
Dump trucks on the other hand have the dump bed as part of the truck. You cannot separate the dump bed on a dump truck from the truck. The controls for lifting the dump bed of the dump truck are inside the cab of the truck whereas for dump trailer the controls are on the dump bed itself so the operator has to walk out to the trailer to dump the bed unless it is rigged so he can do it from inside the cab of his truck.
It's not that one is any better than the other it just depends on what you want to use it for.