3D printing, i.e. a rapid prototyping technique, which is a digital document based on the model, the use of powdered metal or plastic materials may be bonded by way of the printed layer by layer technology to construct the object.
3D printing materials are usually printers using digital technology to achieve. Often in the mold manufacturing, industrial design and other fields are used to make the model, and then gradually for direct manufacturing of some products, there have been made using this technique to print parts. The technology in the jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education, GIS, civil engineering, guns, and other fields have applied.
Everyday life of ordinary printer can print flat items used computer design, and the so-called ordinary printers and 3D printer works basically the same, but somewhat different printing materials, printing materials are ordinary printer ink and paper, while the 3D printer built with metal , ceramic, plastic, sand and other different “printed materials”, are real materials, the printer connected to the computer through computer control can be “printed material” layer laminated together, eventually became the blueprint on your computer kind. In layman’s terms, 3D printer can “print” of a 3D object in real devices, such as printing a robot toy car printing, printing of various models, and even food, etc.. The reason colloquially called “printer” is a reference to the technical principles of ordinary printer, because the process of layering and ink-jet printing process is very similar. The three-dimensional printing technology called 3D printing technology. 
There are many different 3D printing techniques. They differ in the way that the material is available, and to create build parts with different layers.  3D printing materials are commonly used in fiberglass nylon, durable nylon material, gypsum materials, aluminum, titanium, stainless steel, silver, gold, rubber-like material.
|press||熔融沉积式 (FDM）||Plastics molding|
|选择性激光熔化成型(SLM)||Titanium alloy，Cobalt chromium alloy, stainless steel, aluminum|
|powder spray 3D printing||石膏3D打印 (PP)||Gypsum|
|Layer press||分层实体制造（LOM）||Paper, plastic film, metal film|
|数字光处理 (DLP)||Photocurable resin|
3D printing technology is not used in mass production, so some experts advocate 3D printing is the third industrial revolution, this argument is just agimmick.Foxconn OEM for Apple iPhonehas been for many years.Gou made with 3D printing phones to illustrate 3D printing products can not only see, because we can not add electronic components, electronic productscan not be produced as the amount of these products.3D printing even without the production of electronic products,but by material constraints,other products can be produced very little, “even if the products produced, can not mass production, but also on the brokenYishuai.
“3D printingis indeed more suitable for some small-scale manufacturing,especially high-end customized products, such asauto parts manufacturing, although the main material is plastic, but the future of metallic materia ls will certainly be applied to 3D printing in the past,” said Crump, 3D printing technology has entered thedental, jewelry, medical industry,the scope of future applications will be more widely available.