When you open a 3D object (STL file), you need speed and a good interface to see every detail in that 3D object. Using the STL viewer, you can view every part of a 3D object from all sides of the object.

With the ability to add shaded skins, you can see what each part should/will look like in real life. Dynamic rotation will allow you to rotate the object to see every detail on every side of the 3D object. Using wireframe and rotating simultaneously, you can see all the elements that create a 3D object as a whole.