Look at the size of the hand in the background, apparently stroking this cat? If it were really that size the cat would be as big as a pony! How does this work? The cat was very close to the camera and appears large, the hand is my hubby’s, he sat about a foot away and this is his right hand, furthest away from the cat. It’s a bit blurred because it’s at the back. This is called depth of field. If you think of a photo as being in layers from the closest layer to the lens going backwards in slices then the deepest part of the feild of view is at the back. If you have a shallow field only the things at a certain distance will be in focus. With a deep feild all or most of the photo will be in focus. This is most noticeable in the deep field view of the universe with the Hubble Space telescope. In the pictures from that you can keep zooming in to see more and more detail. Sorry for the non technical explanation!