The document discusses how 3D printing will change the world in 9 ways. It will allow for lighter and stronger planes and cars by printing complex metal parts. Houses can be 3D printed more quickly and cheaply. Organs and tissues can be printed for transplants. Custom prosthetics can be printed. Manufacturing will be more flexible by printing on demand. Space exploration will be helped by the ability to print tools and parts. Pollution can be reduced by minimizing waste in manufacturing. Food can potentially be 3D printed as well. Overall, 3D printing is an innovative technology that will revolutionize many industries.