The word “truck” comes from the Greek “trochos”, meaning “wheel.” The big wheels of wagons were called trucks. A truck is a large vehicle used for transporting bulk goods, materials, or equipment. When the gasoline-engine driven trucks came into fashion, these were called “motor trucks.” A small vehicle with an open back is called “utility vehicle” or a pick-up and the word “truck” is reserved for larger vehicles. Almost all trucks share a common construction: they are made of a chassis, a cab, an area for placing cargo or equipment, axles, suspension and wheels, an engine and a drivetrain. Pneumatic, hydraulic, water, and electrical systems may also be identified. They are complex machines. Many also tow one or more trailers or semi-trailers.

Trucks can use all sorts of engines. Small trucks such as SUVs or pickups, and even light medium-duty commercial trucks will use gasoline engines. Most heavier trucks use four stroke turbo intercooler diesel engines, although there are alternatives. Huge off-highway trucks use locomotive-type of engines. North American manufactured highway trucks almost always use an engine built by a third party, such as CAT, Cummins, or Detroit Diesel. The only exceptions to this are Volvo WG64 Trucks and Mack Trucks, which are available with Volvo and Mack diesel engines, respectively, and Freightliner, a subsidiary of DaimlerChrysler, which are available with Mercedes-Benz and Detroit Diesel engines. Trucks and busses built by the Navistar International can also contain International engines.

Small trucks use the same type of transmissions as almost all cars which have either an automatic transmission or a manual transmission with synchronisers. Bigger trucks often use manual transmissions without synchronisers which have less bulk and weight although synchromesh transmissions are used in larger trucks as well. Double clutching allows the driver to control the engine and transmission revolutions to synchronize, so that a smooth shift can be made. The so called skip changing is also widely used, in principle operation is the same but it requires neutral be held slightly longer than single gearchange. Automatic and semi-automatic transmissions for heavy trucks are becoming more and more common, due to advances both in transmission and engine power. Quality among all heavy duty trucks manufacturers in general is improving, however industry insiders will testify that the industry has a long way to go before they achieve the quality levels reached by automobile manufacturers.