Bitcoin (abbreviated as BTC) sounds difficult to understand, but in fact, the definition of bitcoin is very easy to understand. Bitcoin is a digital currency with a total amount of 21 million. Like the Internet, it has the characteristics of decentralization, globalization and anonymity. Transferring bitcoin to the other side of the earth is as simple, low-cost and unlimited as sending e-mail. Bitcoin is therefore used in cross-border trade, payment, remittance and other fields.