Stablecoins are a type of cryptocurrency designed to maintain a stable value, typically pegged to a fiat currency like the US dollar or another asset, such as gold. The primary goal of stablecoins is to combine the benefits of digital currencies (like fast transactions and decentralization) with the price stability of traditional currencies.

Stablecoins maintain their value through various mechanisms:

1. Fiat-collateralized stablecoins: These are backed by reserves of fiat currency held in a bank or a trusted third party. For example, each issued stablecoin is equivalent to a unit of currency like USD, ensuring that the stablecoin can always be redeemed for the equivalent fiat amount. Examples include Tether (USDT) and USD Coin (USDC).

2. Crypto-collateralized stablecoins: These are backed by other cryptocurrencies as collateral. Since cryptocurrencies are volatile, these stablecoins are often over-collateralized to absorb price fluctuations. DAI is a well-known example, where users lock up Ethereum (ETH) as collateral to generate DAI tokens.

3. Algorithmic stablecoins: These rely on algorithms and smart contracts to control the supply of the stablecoin. When the price exceeds the peg, new coins are issued to reduce the price, and when the price falls below the peg, coins are bought back or burned to increase the price.

By using these methods, stablecoins aim to provide a reliable medium of exchange and store of value within the volatile cryptocurrency market.