Rack or Chassis
A chassis is the physical frame or structure of an automobile, an airplane, a desktop computer, or other multi-component device.
A Rack is the framework, typically with rails, bars, hooks, or pegs, for holding or storing things.
6ES5710-0SA41 - Siemens
SIMATIC S5, MOUNTING RACK FOR PC S5-110 FOR 16 Input/Output ModuleS..
6ES5710-0SA11 - Siemens
SIMATIC S5, MOUNTING RACK FOR PC S5-110 FOR 8 Input/Output ModuleS..