The word 'truck' is believed to be a derivative of Greek word - "trochos" which takes the meaning of a wheel. Lorry is yet another term used in this conjunction in United Kingdom whereas wagons with large wheels are known as trucks in North America. Pickup trucks, semi trucks, GMC trucks are the variants that are available. In countries like New Zealand and Australia a small vehicle with open back is known as 'ute' (abbreviated form of 'utility vehicle') or also known as pick-up. In the US only large vehicles used in commercial purposes are called as trucks.
The various important parts of the truck are the Engine, the Drive train and the frame.
Engine: An Engine forms the most important part of a truck as it decides the running capability of a truck and has to be carefully chosen to match the application for which the truck is intended to be used. Gasoline engines are generally used by small trucks like the pickups or SUVs (Sport Utility Vehicles) and also by the medium-duty trucks. However heavier trucks generally use four stroke turbo intercooler diesel engines and highway trucks employ locomotive-type engines which are either two-stroke or a V12 Detroit diesel engine. Most of the truck manufacturers in North America outsource the engine, whereas companies like Volvo and Mack Trucks use their own engines. Euro 5 regulations are complied with by all the truck engines in European nations in the interest of the environment.
Drive Train: Light duty trucks use transmission method similar to that of the cars which are either automatic or manual with synchornisers. Heavier trucks however use manual transmission without synchroniser that is less bulky. Crash boxes (transmissions without synchronizers) have a requirement of employing double clutching for every shift, called as "floating". Generally North American setups include 9,10,13,15 and 18 speed levels. Semi-automatic or fully automatic transmission system is generally preferred to reduce the fuel consumption. In European market the gears may be of 8, 10 and 12 in case of manual transmission while for automatic transmission it might range anywhere between 5-12 gears. The trucks generally have range shift pattern in the gear system.
Frame: Two parallel boxed rails held together by cross members are the main composites of the frame of a truck. They may also be called as ladder frames since they resemble that of a ladder when tipped on end. Crossmembers are mostly attached to frame rails by using rivets or bolts, but sometimes may be welded in case of heavy duty application. The material used to make frame is generally steel but aluminum can also be a substitute to it.
Although trucks contribute to some pollution, they eject fewer air polluting emissions when compared to a car or any other vehicle, but still it contributes to a high level of sound pollution.