3D printing is a phrase used to describe the process of creating
three dimensional objects from digital file using a materials printer, in a manner similar to printing images on paper. The term is most closely associated with
additive manufacturing technology, where an object is created by laying down successive layers of material.
[1] Recently the term is increasingly being used to describe all types of
additive manufacturing processes, or even other types of
rapid prototyping technology.
Since 2003 there has been large growth in the sale of 3D printers. Additionally, the cost of 3D printers has gone down.
[2]The technology also finds use in the fields of jewelry, footwear,
industrial design, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education, geographic information systems, civil engineering, and many others.
Source :
http://en.wikipedia.org/wiki/3D_printing