What I know is that stable coins are USDT and maybe there are others but I don't know yet. The lowest price of USDT if I'm not mistaken is $ 0.9. Because the USDT is supported by the US dollar, which means it will most likely be worth the dollar. This is what might be called stable coins.
USDT is indeed the most popular among stable coins and is also proven to be stable because it always gets dollar prices.
but actually there are some other stable coins but not as stable as USDT.