Shannon's source coding theorem

Shannon's source coding theorem says that if you have data, you can use something called 'coding' to represent that data using fewer bits. This is like when you play a game, and you want to write down the score so that you can remember it later. If the game had 10 points, and the two players got a 4 and a 6, instead of writing down 4, 6 you could write down 01, 10 - and then you've saved some room because you used only two bits in-stead of four. Shannon's source coding theorem states that this kind of coding - where you use fewer bits to represent the data- can always be done.