The capital of a country is wherever the country says it is - it's usually the seat of government, but not always. For instance, the official capital of the Netherlands is Amsterdam, but the seat of government is in The Hague. It can work the other way round too: sometimes other governments refuse to recognise a country's choice of capital. Israel made Jerusalem it's capital after the 1967 war, but just about no country officially recognised this, and the foreign embassies to Israel remain in Tel Aviv, the old capital.