Base currency
The first currency in the pair is the base. On EUR/USD, the base is the euro. On GBP/JPY, the base is the pound. Everything you see on the chart is expressed in terms of the base — one unit of it, priced against the other currency.
Quote currency
The second currency in the pair is the quote (sometimes called the counter). It's the currency the base is being priced in. On EUR/USD at 1.0850, the quote is USD, and the quote is telling you that one euro is currently worth 1.0850 US dollars.
If the pair rises to 1.0900, the base has strengthened relative to the quote — one euro now buys more dollars. If it falls to 1.0800, the base has weakened — one euro now buys fewer dollars.
Major pairs
Major pairs are those that include the US dollar and one of the other most-traded currencies: EUR/USD, GBP/USD, USD/JPY, USD/CHF, AUD/USD, NZD/USD and USD/CAD. They dominate volume, they have the tightest spreads, and they react most cleanly to macroeconomic news. If you're new, spend your first year here.
Minor pairs
Minor pairs (also called crosses) are pairs of major currencies that don't include the US dollar — EUR/GBP, EUR/JPY, GBP/JPY, AUD/NZD and so on. They're still highly liquid, but spreads are typically a little wider than the majors and moves can be less clean because you're seeing the interaction of two non-USD stories at once.
Exotic pairs
Exotic pairs combine a major currency with the currency of a smaller or emerging economy — USD/TRY, USD/ZAR, USD/MXN, EUR/PLN. Spreads are much wider, liquidity is thinner, and moves can be violent around local news or political events. Exotics are perfectly tradable, but they demand smaller position sizes and more caution.
Why EUR/USD is the world's most traded pair
EUR/USD represents the two largest economic blocs on the planet — the eurozone and the United States. That single fact drives its dominance. Every global bank quotes it, every algorithm reacts to it, and every macro trader watches it. The result is astonishing liquidity: the tightest spreads in FX, the deepest order book, and price action that reflects genuine supply and demand rather than a single participant pushing the market around.
For a beginner, that's ideal. There's nowhere better to learn how a market behaves than in the pair with the deepest liquidity.
What causes one currency to strengthen against another
A currency strengthens when the market believes it will offer better relative returns, better relative safety, or better relative growth than the other side of the pair. Every driver you'll read about — interest rates, inflation, jobs, growth, central bank language, geopolitical risk — feeds into one of those three questions.
That's why FX moves are always about the pair as a whole. EUR/USD can rise because the euro is genuinely strengthening, because the dollar is weakening, or because both are happening at once. Looking at a single chart never tells you which. The dollar index and cross-rates fill in the picture and help you see which side of the pair is doing the work.
A practical example
Say US inflation prints hotter than expected. The market immediately raises the odds of the Federal Reserve holding rates higher for longer. That makes the dollar more attractive relative to other currencies, and USD-quoted majors like EUR/USD and GBP/USD fall while USD/JPY rises. All three moves are the same story: the dollar is doing the work.
Key takeaways
- Every quote is a ratio — the base priced in the quote currency
- Majors include USD and offer the tightest spreads and deepest liquidity
- Minors are non-USD crosses; exotics involve smaller economies and wider spreads
- EUR/USD dominates because it links the two largest economic blocs
- A currency strengthens when the market prefers its relative returns, safety or growth
- Always ask which side of the pair is doing the moving — the answer changes the trade