Bitcoin is a digital currency created by an unknown person using the alias Satoshi Nakamoto and operates on a decentralized peer-to-peer network without any central authority or government involvement. It can be used to send or receive money internationally with very low transaction fees compared to traditional payment methods. The network works by having users validate transactions through mining and maintaining a public record of all transactions in the blockchain. While it offers advantages like anonymity and lack of third party control, bitcoin also faces issues with volatility, irreversible payments, and lack of anonymity in transactions.