Refers to the money officially used in a country or region, or to currencies as units traded or exchanged.
日本の通貨は円です。
Japan's currency is the yen.
海外旅行の前に現地の通貨に両替した。
Before traveling abroad, I exchanged money into the local currency.
The central bank issued a new currency.
The value of the yen as a currency is falling.
Before the trip, I exchanged dollars for the local currency.
Recently, this country's currency has been fluctuating significantly.
key currency
cryptocurrency