It's a cryptocurrency whose value is pinned to a traditional currency because the organizational backer is willing to issue and redeem it 1:1, but it can be traded using cryptocurrency mechanisms.

eCoins backed by stable assets to reduce their volatility. It looks suspiciously like regular money.

https://en.wikipedia.org/wiki/Stablecoin

The value vs USD doesn't change.

It is a $25 billion market that has grown over most of the last decade. Expected to continue growing at a fast pace, with all major central banks looking to release their own version for their respective monetary unions.

They are digital assets that are convertible one for one to fiat currencies or assets held by a custodian's account with a bank or brokerage. Not all are convertible and they maintain their stable exchange rate by other means.

They primarily use blockchains like Ethereum for their settlement layer, while keeping their fixed exchange rate, so therefore they inherit all the technology to leap frog the legacy financial system and service people marginalized from that system.