A stablecoin is an asset that is 1:1 with the Dollar or other assets, as specified by the issuing entity. A stablecoin can be used as a replacement for the Dollar, and can be transferred from one address to another similar to cryptocurrencies.
On Stellar, AnchorUSD's stablecoin "USD" is 1:1 with the United States Dollar. AnchorUSD has a set of rules in place for entities who want to transact in its asset. These rules include KYC and AML verification, along with a registration on anchorusd.com.