There’s a lot of complicated forces at play, and this isn’t in my particular field of expertise, but inflation is basically when the supply of money increases, but the actual supply of things money can buy doesnt keep up.

Think of an (extremely oversimplified) economy: one person farms, and another person raises cattle. They’ve agreed to use red rocks to symbolize trades, due to the fact that the rancher can work all year, but the farmer only provides produce with the harvest seasons.

One year, each person finds an extra cache of red rocks, but the extra currency doesn’t actually allow either individual to farm or ranch any more. Each one knows that the rocks are more plentiful, and so less valuable. The rancher expects more rocks for his meat, because he knows he’ll need more rocks to buy produce.

The two main ways that currency is created (again, within my limited knowledge) is through minting and fractional reserve banking. There’s plenty of explanations for either, so I’ll gloss over. On the other hand, inflation can occur if production decreases, or even fails to increase as fast as expected.