This is a £10 note. It's a very common form of money, even though, it isn't even really money.The writing beneath "Bank of England" reads "I promise to pay the bearer on demand the sum of 10 punds". This means that the £10 note is not actually money, but a very intricate IOU. This is the same with any bank note of the pound sterling.
Think about it. Next time you check your wallet, and you just have notes, you don't actually have money. This may seem kind of wierd, but you'll probably end up not having to pay your share for a meal.
