View Extrude
Extrude, or extrusion, is a process that will pull a material through a patterned shape in order to create a 3D object. Much like you can do with play-dough, the Extrude NURBs tool that will take a shape you create and sweep it away from the source shape to create a 3D object, just as in extrusion in the physical world.
One of the benefits of Cinema 4D is that you can have much more control over your object than you could with a real-world extrusion, and for much less effort on your part. You can control the extrusion direction, and cap characteristics, as well as tweak the polygon mesh to meet your modeling needs.