$BNB (Binance Coin) is the native cryptocurrency of the Binance blockchain ecosystem. It was initially launched in 2017 as an ERC-20 token on the Ethereum network, but later migrated to its own Binance Chain blockchain.

BNB serves several key functions within the Binance ecosystem. Firstly, it is used to pay for trading fees on the Binance cryptocurrency exchange, with users receiving a discount when using BNB to pay their fees. Secondly, BNB can be used to pay for various services and products offered by Binance, such as Binance Launchpad (for initial coin offerings) and Binance Visa Card.

Additionally, BNB is used for governance purposes, allowing holders to vote on proposals and participate in the decision-making process of the Binance blockchain. The token also has a deflationary mechanism, where a portion of the BNB supply is regularly burned, reducing the total circulating supply over time.

Overall, BNB is a crucial component of the Binance ecosystem, providing utility, governance, and a deflationary mechanism that supports the growth and development of the Binance platform and its associated blockchain technologies.