What is 3D printing
3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers.3D printing is a method of manufacturing everything from shoes to jewelery, to guns and aerospace parts, using a computer-controlled printer.

Different printing techniques
Fused deposition modeling – The most common 3D printing method is fused deposition modeling (FDM). The raw material with this process is a spool of plastic or metal wire, which is melted and placed by the printer’s nozzle. It quickly hardens, and then the next layer can be added.
Inkjet printing — Using special inks (resins and binders) it’s possible to build up a 3D model using a device that’s very similar to a home or office inkjet printer.
Digital light processing – With DLP (yes, the same technology behind DLP projectors), a vat of liquid polymer is turned into a very strong solid by exposing it to light.
Advantages of 3D Printing
1. Increase Innovation
2. Improve Communication
3. Cheap Manufacturing
4. Quick Production
5. Less waste
6. Speed Time To Market
7. Reduce Development Costs
8. Better quality
9. Accessibility
10. Sustainability
Source: en.wikipedia.org