Major pairs include the US dollar (USD) and are the most traded, such as EUR/USD, GBP/USD, USD/JPY, and USD/CHF. They are known for high liquidity and lower volatility. Minor pairs do not include the US dollar and feature other major currencies, like EUR/GBP, EUR/AUD, and GBP/JPY. These pairs have lower liquidity and higher volatility compared to major pairs.