What is the difference between atmospheric pressure and altitude?

Altitude is basically height or depth, depending on how it is used and where it is used. Atmospheric altitude refers to the height from the ocean level to the tip of our atmosphere, the exosphere. The less air that there is, the less weight and pressure is there. As elevation increases, the pressure and the density of air decreases. When something is pushed over something else, the force created because of the push is pressure. Atmospheric pressure would mean that the force that pushes anything else is the weight of the air. Thus, as altitude increases, atmospheric pressure decreases.