Binance Coin (BNB) is the liquidity token that is used on the Binance cryptocurrency exchange. Binance is one of the largest cryptocurrency exchanges in the world and the BNB coins are used on the exchange as one of the cross assets. The people behind the BNB token are the same leaders in charge of the Binance exchange including Zhao Changpeng, a well known cryptocurrency personality.
BNB coins are ERC20 tokens and were sold to the public in a token sale in July of 2017. The BNB coin can be used by traders on the Binance platform to pay for fees. For those traders who are making use of the BNB, the exchange will rebate you the fees on a sliding scale over a period of 5 years.
The BNB also has something called the quarterly "coin burn". The exchange will burn 20% of the profits that they make from the exchange and buy back the BNB. These will be "burned" or destroyed. This will continue until Binance has burned half of the total coin supply.
There are also a number of other initiatives that are being developed by Binance that could increase demand for BNB tokens. These include the likes of the Binance Chain which has launched the Binance DEX. This decentralised exchange will use the BNB tokens as the base liquidity token in the exchange which could increase demand.
Similarly, Binance has just released their "Launchpad" which will serve as a platform whereby projects can issue their own tokens in exchange for BNB tokens. This would increase demand for BNB tokens as people try to partake in these crowd sales. This has also been used successfully by projects recently including the BitTorrent (BTT) token raise.
BNB tokens are relatively stable and there is a large amount of liquidity should on the exchanges. Most of their volume is available on the Binance exchange but this could move onto the Binance DEX as it is launched.