3d printing is the common term used for any technology that creates an object layer by layer, also known as additive manufacturing.
The benefits of this are nearly unlimited but here a few.
* The amount of materials is reduced. With other methods like subtractive manufacturing you can have up to 90% waste in order to make your item. 3d printing will have very little to none only putting material where its needed.
* Creative Freedom. This aspect of 3d printing can be a very fun part because it allows your ideas to become reality. either personalize your pen or make everything in your house to your hearts content, really the limits end with you on this one.
* Rapid Prototyping. If your trying to create a new design or invention and not sure how your ideas will relate to the real world applications don't worry you can try out your initial idea and make alterations shortly after to get the final concept before bringing the concept to your investors and have a physical object in hand to show off.