Major currency pairs
The majors pair the US dollar with another big currency: EUR/USD, USD/JPY, GBP/USD, USD/CHF, AUD/USD, USD/CAD and NZD/USD.
These are the most traded pairs in the world, so they are the most liquid and usually the cheapest to trade. EUR/USD leads forex volumes by a wide margin, in a market that turns over about $7.5 trillion a day according to the BIS (2022).
Their status has regulatory consequences: under ESMA rules in the EU, and the matching FCA rules in the UK, retail clients get a maximum of 30:1 leverage on majors, against 20:1 on other pairs. ASIC applies the same caps in Australia.
When you start out, focusing on two or three majors makes sense: tight spreads, plenty of information and price behaviour you get to know over the weeks.