This document provides an introduction to 3D printing. It explains that 3D printing begins with an imagination and digital design of an object, which is then printed physically. The first 3D printers were created to produce prototypes of objects that could be touched. The printing process involves designing an object on a computer, plugging it into a 3D printer, which then prints the exact object. 3D printing is valuable as it allows people to make customized parts for hobbies or other uses.