白车身的定义：白车身（Body in White）按照车身术语标准和教科书上的定义，是指装焊完毕尚未涂装的车身。涂装后的白车身加上内外饰（包括仪表板、座椅、风挡玻璃、地毯、内饰护板等）和电子电器系统（音响、线束、开关等），再加上底盘系统（包括制动、悬架系统等），再加上动力总成系统（包括发动机、变速箱等）就组成了整车。

车身定义

以下是维基百科对白车身的定义：

Body in white or BIW refers to the stage in automotive design or automobile manufacturing in which a car body's sheet metal components have been welded together — but before moving parts (doors, hoods, and deck lids as well as fenders) the motor, chassis sub-assemblies, or trim (glass, seats, upholstery, electronics, etc.) have been added and before painting.

The name derives from manufacturing practices before steel unibody or monocoque bodies — when automobile bodies were made by outside firms on a separate chassis with an engine, suspension, and fenders attached. The manufacturers built or purchased wooden bodies (with thin, non-structural metal sheets on the outside) to bolt onto the frame. The bodies were painted white prior to the final color.