$BNB

Refers to the trading relationship between BNB (Binance Coin) and another cryptocurrency or fiat currency on an exchange. Essentially, when you see a pair like BNB/USDT, it means you can exchange BNB for USDT (Tether) and vice versa. Another example could be BNB/BTC, where the pair indicates the possibility of exchanging BNB for Bitcoin.

These pairs are fundamental in the cryptocurrency ecosystem, as they allow users to perform trading operations, determining the relative value of one currency in terms of the other and facilitating liquidity in the market.