What causes the red mark on your skin after sitting in a position for too long?

Example: Leaning on your hand while surfing the internet, after a while, there is a red mark on my face. It eventually fades away.


I want to know what the actual process is beneath the skin. Why does it turn red and eventually go away?What causes the red mark on your skin after sitting in a position for too long?
it's just a pressure mark when you apply pressure on any part of the body you force the blood to re-route in that area or slow down its route and once you move the object off the area the blood comes back (normally) and your normal color comes back