This website explains how 3D printers can print something that is three dimensional. First there need to be a designing software to design the object. The 3D object is printed by stacking thousands of 2D layers to turn it into a 3D object. This process is explained in the movie Flatland. The site also mentions that the material that can be used to print the objects are unlimited. People have used plastic, rubber and even chocolate. In the future, this technology can enable to let people make all sorts of useful things at home, and our lives would be more efficient.