Relative Motion

Relative Motion is motion as observed from or referred to some material system constituting a frame of reference. So pretty much it's the idea that motion is all relative. Relative to me the moon follows me in the car at night, but relative to the car, the moon does not move at all.

The picture above is an example of relative motion. The two girls in the back (myself and my friend) are moving out to sea relative to the shore. The reason is because the shore doesn't move at all, but the water does. Relative to the water we're not really moving, but because the shore is stationary we are moving farther and farther away from the shore. Relative to us, the shore appears to be moving because we are moving out to sea when really it is stationary. Everyone on the beach is moving relative to us because we are moving along with the current, where in fact they are stationary as well.