A 3-D printer is different from ones that use ink and paper. 3-D printers use materials such as plastic or metal. They create three-dimensional objects with height, length, and width.
3-D printers are better in many ways than old types of manufacturing. People can make things as they need them. That can save time and money.
For example, shipping supplies from Earth to the International Space Station costs $10,000 a pound! Astronauts with a 3-D printer could simply print items as they need them.
3-D printing also reduces waste. It uses just enough material to make an object.
Another plus is that these printers can make complex shapes. People can get prosthetic limbs specially made for their bodies.