There are several ways of 3D Photography. I started out with the very old stereophotography. To get a stereoscopic image, or 3D, you need 2 pictures with slightly different point of views. Those 2 images are so processed that an illusion of depth is created. The most common way is the use of 3D glasses – mostly red-cyan. There are other ways like freeview. on this site i try to explain a little about this fantastic technique and how easy it can be to create 3D images. You can start by simply using your phone!
Another approach is the use of lenticular lenses. The final image can be viewed without any tools like glasses. With this technique our eyes sees different pictures printed under the lens. So the illusion of depth is generated. This is a great and impressing way of showing 3D Art and Photography. But it comes with a lot of limitations and its a big challange once you go down that road.