GDP per capita is the economy's output divided by its population, in euros per inhabitant. It is the most widely used shorthand for how prosperous a country is on average.
What it captures — and misses
It captures average income generated per person, which tracks living standards reasonably well.
It is an average, so it says nothing about how income is distributed.
Comparing across currencies and price levels requires care; within the euro area the comparison is cleaner.
The comparison that matters
GDP per capita is where the EU's growth gap with the United States is most visible: the difference in income per head has widened over the past two decades. It is the number to watch when asking whether Europe is keeping pace.
Source: Eurostat national accounts, annual, current prices.