You may already read alot of news or media talk about printing rabbit heart , boat or building.
Those media always make 3D printing technology sound like just one push button it done by itself.
Well I am Bruce lets back to basic. 3D Printing is a desktop version of Additive manufacuring.
Yes, in theory it can build amos everything , But!
3D Printing technology is not one thing. is a category it includes the plenty type of technology.
One of the most common desktop 3D Printing is FDM technology.
FDM Fused Deposition Modeling/ FFF Fused Filament Fabrication
side noted: This two are same thing. If you interested why one technology got two name click here
FDM/FFF the additive manufacturing method in which a detail is created layer by layer by melting a plastic wire and applying it through a heated nozzle.
check the picture below :