Coffee is the world’s most-traded commodity after oil – which makes sense, since it helps you to get through a busy day. But how does it actually work?
Coffee blocks the receptors of a chemical called Adenosine, which normally has the effect of making you tired and telling your brain to go to sleep. However, as caffeine keeps blocking the adenosine-receptors, more receptors will pop up – with the result that you will need more coffee to feel the effect of the caffeine.
Source for more knowledge: YouTube/ASAPScience