Stablecoins are probably the most fascinating cryptocurrency invention that fill the gap in volatility between digital money and the stability of fiat currencies. Price stability is their nature, normally pegged to fiat currency such as the US dollar, euro, or other assets. However, it is not even the mechanism of backing that contributes to the trustworthiness of stablecoins. It is also the blockchain activity that determines their issuance, circulation, and redemption. For the purpose of understanding how stablecoins work, there is a need to discuss the inner mechanism of their blockchain architecture.