Inventor gives you the ability to take an Idea of something you want to make and creating blueprints for it.  You can make the object and add dimensions in 2D but then you can also extrude that object and make it 3 dimensional.  This creation can then be transferred to a 3D printer and made into a real life mold.

First you must sketch your widgets on paper

After you create the sketches on paper you can then create the sketch in inventor creating a 3 dimensional object

Now you can transfer the object over to maker bot and set the dimensions to the size you want the object to be printed at.

Finished Widget

Overall using inventor I was able to learn how to think of and something and take it out of my head and make into something that I can hold in my hand.  This is just a small part of what you can do on this website and it gives you the ability to learn and make so many things and gain skills that can help in the future.