3d Printing! It's Trending; Lets learn about it.

3D printing, or additive manufacturing, is the construction of a three-dimensional object from a CAD model or a digital 3D Model. The term "3D printing" can refer to a variety of processes in which material is joined or solidified under computer control to create a three-dimensional object, with material being added together (such as liquid molecules or powder grains being fused together), typically layer by layer.
With the help of below image you can understand the concept.


Who uses this technology?
Even the best artists struggle to show us what real-world objects look like in all their three-dimensional (3D) glory. Most of the time that doesn't matter—looking at a photo or sketch gives us a good-enough idea. But if you're in the business of developing new products and you need to show them off to clients or customers, nothing beats having a prototype: a model you can touch, hold, and feel. Only trouble is, models take ages to make by hand and machines that can make "rapid prototypes" cost a fortune (up to a half million dollars). Hurrah, then for 3D printers, which work a bit like inkjets and build up 3D models layer by layer at up to 10 times the speed and a fifth the cost. How exactly do they work? Let's take a closer look!


3d printed Parts.


Jet engine model.


Tea cups


Architecture model plan

Imagine building a conventional wooden prototype of a car. You'd start off with a block of solid wood and carve inward, like a sculptor, gradually revealing the object "hidden" inside. Or if you wanted to make an architect's model of a house, you'd construct it like a real, prefabricated house, probably by cutting miniature replicas of the walls out of card and gluing them together. Now a laser could easily carve wood into shape and it's not beyond the realms of possibility to train a robot to stick cardboard together—but 3D printers don't work in either of these ways!

A typical 3D printer is very much like an inkjet printer operated from a computer. It builds up a 3D model one layer at a time, from the bottom upward, by repeatedly printing over the same area in a method known as fused depositional modeling (FDM). Working entirely automatically, the printer creates a model over a period of hours by turning a 3D CAD drawing into lots of two-dimensional, cross-sectional layers—effectively separate 2D prints that sit one on top of another, but without the paper in between. Instead of using ink, which would never build up to much volume, the printer deposits layers of molten plastic or powder and fuses them together (and to the existing structure) with adhesive or ultraviolet light.

Advantages 

• Makers of 3D printers claim they are up to 10 times faster than other methods and 5 times cheaper, so they offer big advantages for people who need rapid prototypes in hours rather than days. 
• They're also reasonably small, safe, easy-to-use, and reliable (features that have made them increasingly popular in places such as design/engineering schools).
• On the downside, the finish of the models they produce is usually inferior to those produced with higher-end RP machines. 

Disadvantages

• High-end 3D printers they are still expensive, they're a fraction the cost of more sophisticated RP machines, and vastly cheaper machines are also available.
• The choice of materials is often limited to just one or two, the colors may be crude, and the texture may not reflect the intended finish of the product very well. 
• Generally, then, 3D-printed models may be better for rough, early visualizations of new products.

Applications

• Rapid Prototyping.
• Production parts
• Manufacturing Tooling