A stablecoin is a token engineered to hold the price of a reference asset, almost always a fiat currency: one USDC aims to be worth one dollar today, tomorrow, and at settlement. Issuers back that promise with reserves (bank deposits, T-bills, or the reference currency itself) and publish attestations so holders can check.
Because the price stands still while the settlement stays on-chain, stablecoins do the job cash does in a portfolio and a ledger does in a payment system. Merchants price in them without FX drama; treasurers hold them between settlements; rails clear them with crypto finality.
Twenty-four stablecoins trade on U.CASH across the dollar, euro, yen, and fourteen other currencies, each with its issuer, peg, and reserve posture on its own page. Checkouts price them from fiat FX tables or their own market feed, never from a thin pool.
Every term behind the rails, the assets, and the settlement.