Dump trucks usually have a larger steel cargo box that primarily hauls road construction or maintenance material. These trucks might also be called "tipper trucks" by some. But dump trucks typically are classified as those that are primarily suitable for very heavy duty use often in construction duty. However, tipper trucks may also include smaller light duty vehicles like a standard pickup with an aftermarket cargo box that tilts to unload various material. Also, a standard straight truck that may have a cargo box constructed of wooden slats that hauls agricultural material like feed corn, oats, wheat, etc. that tilts back to unload it's cargo. Something of that nature.