Base and quote currency confusion: help each other out

In EUR/USD, EUR is the base and USD is the quote. Buying the pair means buying euros and selling dollars; the price is how many dollars one euro costs. It's simple in theory and a source of endless mistakes in practice.

What helped the concept click for you? Post the explanation or example that finally made it stick, or the question you still have.

The base and quote currency guide covers long and short positions from first principles.