For many users of Bitcoin, they will only see the wallet, transaction, Bitcoin address on the web and all should work smoothly following each specific procedures.

Behind this, there is a Public Ledger called “Block Chain” which Bitcoin network shares with everyone.

There is only one correct Public Ledger of Bitcoin in the world and all transactions of Bitcoin has been and will be written on it.

Because there is only one correct Public Ledger (which everyone is sharing together), it is used to verify the validity of each transaction (to avoid any fraudulent activities).

The authenticity of each transaction is also protected by digital signatures corresponding to the sending addresses.