People send each other bitcoins over the network every day. Every transaction is recorded and stored, or else it would not be possible to know who had paid what sums. Every single transaction made during a certain period of time is gathered up by the Bitcoin network to create a list known as a \'block\'.

Bitcoin miners have to confirm every transaction, and then record the details in a general ledger. Traditional money systems allow governments to print money whenever they need to, but Bitcoins are not printed. People discover Bitcoins, and computers right across the world are competing against one another to mine them.

A long list of blocks is known as a blockchain, and they make up the general ledger. Any transaction made between bitcoin addresses can be looked at, at any point of the network. New transactions are added to the blockchain which produces an ever-increasing list which is regularly updated and sent to everyone involved.

Blockchain can never be tampered with because the miners take data from a particular block, and change its form by applying a mathematical formula. What is created is far shorter, and looks like random letters and numbers – and this is known as a hash, which is stored with the block, at the end of the blockchain. It is like a digital wax seal, and people can see if it\'s been tampered with in any way.