The first 3D printer was introduced in 1980 and at that time it was known as the rapid prototyping apparatus. It was named so, as the process was relatively fast and cost effective for creating prototypes. In 1986 the complete patent for the 3D printers was issued to the stereo-lithography apparatus by Chuck Hulls, who later on founded the 3D systems cooperation.
In simple words, a 3D printer creates a three dimensional object by using 3D models of the object to be formed & by using different types of raw material depending upon the type of object to be prepared.