Ordinary printers used in daily life can print computer-designed flat objects. The so-called 3D printer works in the same way as a normal printer, except that the printing materials are somewhat different. The printing materials of ordinary printers are ink and paper, and the 3D printer is equipped with metal. Different kinds of "printing materials" such as ceramics, plastics, sand, etc. are real raw materials. After the printer is connected with the computer, the "printing materials" can be layered by computer control, and finally the blueprint on the computer becomes Real. In layman's terms, a 3D printer is a device that can "print" a real 3D object, such as printing a robot, printing a toy car, printing various models, and even food. The reason why it is commonly referred to as "printer" is to refer to the technical principle of ordinary printers, because the process of layered processing is very similar to inkjet printing. This printing technology is called 3D stereo printing technology. 
There are many different technologies for 3D printing. They differ in that they are created in the same way as the available materials and in different layers. Common materials for 3D printing are nylon glass fiber, polylactic acid, ABS resin, durable nylon material, gypsum material, aluminum material, titanium alloy, stainless steel, silver plated, gold plated, rubber material.