What is the difference between a smart watch and our ordinary watch

Smart watch:It is a watch with a built-in intelligent system, equipped with a smartphone system and connected to the network to achieve multi-functionality, which can synchronize phone calls, text messages, emails, photos, music and so on in the cell phone.

Watch: or known as wristwatch, is an instrument worn on the wrist to keep/show time.

Watches are usually made of leather, rubber, nylon cloth, stainless steel, etc., and the "head" of the watch, which tells the time, is attached to the wrist. So the wristwatch is a watch just say differently.