A vehicle frame or Frame is the main supporting structure of a motor vehicle to which all other components are attached, comparable to the skeleton of an organism.
Until the 1930s, virtually every car had a structural frame, separate from its body. This construction design is known as body-on-frame. Over time, nearly all passenger cars have migrated to unibody construction, meaning their chassis and bodywork has been integrated into one another.
Nearly all trucks, buses, and most pickups continue to use a separate frame as their chassis.
The main functions of a frame in motor vehicles are:
To support the vehicle's mechanical components and body
To deal with static and dynamic loads, without undue deflection or distortion.
The following are the types of frame according to the construction:
Ladder type frame
Off set frame
Off set with cross member frame