BNB is a cryptocurrency (token) that was created by Binance back in 2017. It was first issued and launched during an Initial Coin Offering (ICO) crowdfunding event, which took place between the 26th of June to the 3rd of July.
The token sale offered 100,000,000 units of BNB (50% of the total supply). The issue price was 1 ETH for 2,700 BNB or 1 BTC for 20,000 BNB (around 0.11 USD back then).
BNB was initially issued as an ERC-20 token (on the Ethereum platform), but it will be soon transferred to the main Binance Chain. The initial total supply of BNB was defined as 200,000,000 coins, but due to the regular coin burn events, the supply is gradually decreasing. To learn more about BNB coin burns, please refer to this video at Binance Academy.
BNB has multiple use cases, but within the Binance Exchange ecosystem, it is used as a utility token that allows users to receive discounts when paying for their trading fees. The fee discount is gradually reduced after every quarter until it reaches 0% on the 15th of July, 2021. You can check the discount schedule in this article. Moreover, the fee structure also changes according to the trading volume (30 days) and tier level of the account (more details on this page).
Besides being used by traders to get discounts on their trading fees, BNBs can also be used to pay for travel expenses (such as hotels and flights booking), to buy virtual gifts, to shop using a credit card, and much more.
In addition, you can also make impactful donations to charity through the Binance Charity Foundation (BCF) project. In a near future, BNB will be used as gas on the Binance Chain and the Binance Decentralized Exchange (DEX). Currently, you are able to buy BNB directly on the Binance exchange.