3D printing or additive-fabrication is a process of making three dimensional solid objects from a 3d digital file.
The creation of a 3D printed object is achieved using additive-fabrication. In an additive-fabrication an object is created by laying down plastic layers of material until the object is created. Each of these layers can be seen as a thinly sliced horizontal cross-section of the eventual object.
3D printing is the opposite of subtractive fabiraction which is cutting out / hollowing out a piece of metal or plastic with for instance a milling machine.
3D printing enables you to produce complex (functional) shapes using less material than traditional manufacturing methods
3d printing is one of my favorite hobbies and the wave of the future I believe here are a couple of 3d printers that a personal use that I think are the best for people taking up this great hobby. Who knows maybe one day I can make a career out of 3d printing!!!
under 400 bucks I found mine on sale for 299
You can get fully assembled for a little extra cash or build it yourself for less than 200
more expensive than the Tarantula but very little assembly and overall a better printer 
cheap printer for newbies 
very cheap but you have to build it
more expensive than the Tarantula but easier to build