In Forex you exchange one currency for another with the intention of making a profit. The seven most traded currency pairs in forex are called the Majors.
Compared to other pairs, the Majors share certain characteristics that make them very popular for traders. These characteristics are the reason they represent about 80% of volume traded on the forex market. The reporting in their economies is plentiful and frequent which means that there is more information regarding these currencies. However, their popularity also relies on their liquidity and low volatility. They are also less susceptible to manipulation and have tighter spreads than other currency pairs.