Because soon you will own one
What is 3D Printing and How Does It Work? | Mashable Explains
3D printing has become a much more mainstream technology, with printing machines available in almost every price range. Most people who want a 3D printer can probably find a model they can afford. Despite this, 3D printing is still so new that few people know how it works.
So now is a good time to answer the question "How does 3D printing work?" Chances are you'll end up using one!
There are two broad categories of 3D printing. The 3D printers that you can buy yourself are almost all “additive” machines. In other words, they build 3D objects by adding material (usually in layers) until the object is complete. The 3D printers that people think of when they hear “3D printer” are almost always of the additive variety.
