The trading pair #交易对 is a combination used in cryptocurrency trading to represent the exchange relationship between two different assets. For example, Bitcoin against Ethereum (BTC/ETH), where the currency in the front is the base currency and the one at the back is the quoted currency. It determines the direction of the trade and the way the price is expressed, allowing investors to buy and sell based on the price fluctuations of the trading pair to gain profit from the price difference. Different trading pairs have varying liquidity and price trends in the market, and understanding the characteristics of trading pairs is fundamental to engaging in cryptocurrency trading.