Have you ever held a toy nerf gun and tried to aim through one eye? You shoot the gun and sadly you miss the target. So, a great idea hits you, why not try to aim with the other eye! So you try the same thing but to your surprise your aim is totally off! You then have to adjust and move your arm/aim to a different point. This weird phenomena is known as binocular disparity. This can be explained by the fact that each eye sees the world a big differently, but our brains adaptively use this to judge depth when looking through both eyes. Unfortunately for me I sucked at aiming in general so neither helped me.
Another great example are a pair of binoculars. When we see near, our left and right eye induce the information quite different than that of far objects. Binoculars help put these depths into focus. Without disparity, our judgment of depth would be horrendously poor.