$BTC Bitcoin is the world's first open-source cryptocurrency known as a decentralized digital currency. No financial institution or clearing house is required for transactions here and it is not a currency issued by any country's government.A bitcoin, at its core, is a token representing value. The token is digital (or virtual), and your public key is used to assign it to you. Ownership is transferred when transactions are made to another person's public key. You use your wallet, the mobile application, to send or receive bitcoin.