Bitcoin (₿) is a cryptocurrency and worldwide payment system. It is the first decentralized digital currency, as the system works without a central bank or single administrator. The network is peer-to-peer and transactions take place between users directly, without an intermediary. These transactions are verified by network nodes through the use of cryptography and recorded in a public distributed ledger called a blockchain. Bitcoin was invented by an unknown person or group of people under the name Satoshi Nakamoto and released as open-source software in 2009. And the amount of bitcoin is limited, total supply is 21 million.
Bitcoins are created as a reward for a process known as mining. They can be exchanged for other currencies, products, and services.