To know what is Prefab houses, we should know what is " assembly" first.

(1) How to define "assembly" in the machinery industry

What is "assembly"? "Assembly" is the use of various "components" with different materials, different shapes, and different functions with various devices that can be "assembled", "disassembled", and "replaceable" (that is, repairable) Installed together to form a "complete machine", even a moving machine, or a movable machine.

(2) Professor Ding Chengzhang explained what "assembly" is in the on-site performance of the conference

Taking a mineral water bottle as an example, screwing on the bottle cap is "assembly", unscrewing the bottle cap is "disassembly", and replacing a bottle cap is "replaceable" (repairable);

■If you buy a car with a value of several hundred thousand yuan, and it has not been driven for two days, the tire has blown, so go to the 4S shop to repair it. You say: Master, change a tire. After inspection, the car repairer said: Sorry, your car is not a "fabricated" car, and the tires are "welded" (that is, welded to death) on the car and cannot be "disassembled". You said: What should I do? The car repairer said: Buy another car, but next time you must buy a "fabricated" car instead of this "welded (welded)" car. Because a car is hundreds of thousands, a tire is only a few hundred dollars.

■For many century-old houses with wooden structures in North America, the walls may be damaged due to various reasons. But it doesn't matter. Take two jacks and a beam to jack up the roof or floor system, and you can "disassemble" the old wall and "replace" the new wall. If it is not a "fabricated" building, the whole house can only be "disassembled".