Binance Coin is a cryptocurrency, which is used on the Binance exchange to provide the most comfortable terms of trade
Binance Coin was originally conceived as an instrument for the trading platform, which technically allowed developing both the cryptocurrency and the platform itself. The BNB token is based on the ERC20 protocol, so you can store it on any Ethereum-wallet, as well as on the platform itself, using the functional of the service for payment. Myetherwallet and Mist can be identified among the wallets.
This cryptocurrency is very promising; it is a good option for long-term investment, if you exclude all possible force majors with the exchange.