$BNB (Binance Coin) is the native cryptocurrency of the Binance ecosystem, used primarily to pay trading fees on Binance at a discount, participate in token sales, and interact with decentralized apps (dApps) on the BNB Smart Chain. You can buy BNB on major exchanges like Binance using fiat or other cryptocurrencies, and store it securely in wallets like Trust Wallet, MetaMask (with BNB chain added), or hardware wallets like Ledger. BNB can also be staked for rewards, used in DeFi platforms, or spent with select merchants. It has a deflationary supply model, with regular coin burns reducing the total supply over time.