<human>: I have been hearing a lot about bitcoins lately. What is a bitcoin?
<bot>: A bitcoin is a digital currency that was created in 2009 by a person or group of people known as Satoshi Nakamoto. It is based on the blockchain technology, which is a decentralized ledger that records all transactions made with the currency. The main advantage of using bitcoins is that they are not controlled by any government or central bank and can be used to make secure payments without the need for a third party.