$BNB or Binance Coin, is the native cryptocurrency of the Binance ecosystem, one of the world's largest crypto exchanges. Initially an ERC-20 token on Ethereum, BNB migrated to its own blockchain, the Binance Chain, and later became central to the Binance Smart Chain (now BNB Chain). It offers users reduced trading fees on Binance, powers the DeFi ecosystem on BNB Chain, and is used for various utilities like travel bookings and entertainment. BNB's utility and the continuous expansion of the Binance ecosystem drive its value and widespread adoption.