$ETH refers to trading pairs in the crypto market, representing the exchange rate between two types of assets. For example, the BTC/USDT pair indicates the price of 1 BTC in USDT. There are three main types: crypto-fiat pairs (like ETH/USD), crypto-stablecoin pairs (like SOL/USDT), and crypto-crypto pairs (like ETH/BTC). Choosing the right pair helps investors take advantage of trends, manage risks, and price accurately. Additionally, the liquidity of each pair affects the ability to execute orders. Understanding the mechanics of trading pairs is the first step to building an effective strategy and optimizing profits.