BNB was launched through an initial coin offering in 2017, 11 days before the Binance cryptocurrency exchange went online. It was originally issued as an ERC-20 token running on the Ethereum network, with a total supply capped at 200 million coins, and 100 million BNBs offered in the ICO. However, the ERC-20 BNB coins were swapped with BEP2 BNB on a 1:1 ratio in April 2019 with the launch of the Binance Chain mainnet, and are now no longer hosted on Ethereum.
BNB can be used as a payment method, a utility token to pay for fees on the Binance exchange and for participation in token sales on the Binance launchpad. BNB also powers the Binance DEX (decentralized exchange).