Can someone explain to me what is rendering and how can I use it in SW 2016?
Rendering is the creation of an image, or animation from a CAD model. The image can take many forms, from photo-realistic, to a line drawing, to a cartoon.
In SW2016 you should have an add-on called PhotoView 360. Watch some tutorials, or check the help files for some details on how to arrange lighting, and apply materials to your model(s).
Here are two rendering tutorials which are focused on Keyshot (a rendering program). They should be enough to show you the basic ideas of rendering, even if they are focused on a program other than Photoview 360:
Some Keyshot Tips
More Keyshot and Photoshop Tips