BNB, or Binance Coin, is the native cryptocurrency of Binance, one of the largest cryptocurrency exchanges in the world. Originally launched in 2017 as an ERC-20 token on the Ethereum blockchain, BNB has since migrated to Binance's own blockchain called Binance Chain.

BNB was initially created as a utility token, primarily used for trading fee discounts on the Binance exchange. Over time, its use cases expanded to include:

1. Transaction fees: BNB can be used to pay for transactions on Binance Chain and Binance Smart Chain (BSC), Binance’s blockchain platforms.

2. Staking and liquidity provision: BNB is also used for staking, participating in various DeFi projects, and providing liquidity on platforms built on Binance Smart Chain.

3. Token burns: Binance performs regular "burns" (permanent removal) of BNB to reduce the total supply, which is aimed at increasing its value over time.

4. Utility in dApps: Many decentralized applications (dApps) on the Binance Smart Chain allow or require BNB for interacting with their platforms.

BNB is considered one of the top cryptocurrencies by market capitalization and plays a key role in the Binance ecosystem.