Russia's ruble has tumbled. What does it mean for the wartime economy?

Russia's ruble has fallen a long way in recent months, and the country's central bank has stepped in to try to halt the slide.

Until now, the government stood aside as the declining ruble helped its budget. But a weaker currency also poses the threat of higher prices for everyday people in Russia — and the government has finally moved to halt the drop.

Here are key things to know:

WHY IS THE RUBLE FALLING?

Russia is selling less abroad — mainly reflected in falling revenue from oil and natural gas — and it's importing more. People or companies importing goods to Russia means selling rubles for...