Stable Coins are cryptocurrencies that represent a value of an asset.
Stable Coins promise a stable value in digital form. Depending on the type, a stable coin can represent either a certain amount of fiat currency ($, €, Yen, etc.) or the corresponding amount of commodities (an ounce of gold, a barrel of oil, etc.). This ultimately makes it less complex to circumvent price fluctuations in cryptocurrencies. So basically, a stable coin is a crypto derivative, i.e. the representation of an underlying asset, such as US dollars or gold, in the form of a token. Tether for example is one of the dominant issuer of stablecoins.