In a car, the term chassis means the frame (the metal "skeleton") plus the engine, transmission (gear shift), driveshaft, differential (gears which keep the back wheels moving correctly), and suspension (springs which keep the car above the ground). A body, which is usually not necessary to keep the car together, is built on top of the chassis to complete the car.
A tank (war machine)'s chassis (hull) comprises the bottom part of the tank, which includes the tracks, power plant, driver's seat, and crew compartment.
In computers, the chassis refers to the rigid framework onto which the motherboard, memory, disk drives, and other equipment are mounted. It also supports the shell-like case: the housing that protects all of the vital internal equipment from dust, moisture, and tampering. The term "case modding" refers to the artistic styling of otherwise rather functional and plain computer encasings. Main article: computer case for personal machines or rack mount for commercial grade servers.