A fair reply to "How to buy usdt?" starts with what a stablecoin promises. USDT, the ticker of the Tether token, is a stablecoin: a crypto token built to hold a steady value equal to one unit of a major traditional currency. Players use it to move money into and out of casinos without the daily price swings of bitcoin. What USDT is, how it works, whether it is safe and how people get it are distinct questions, and each has an honest answer with its own limits.
What is USDC? It is another reserve backed stablecoin, issued by a different company from the one behind USDT. The difference between USDC and USDT lies mainly in the issuer, in how each discloses its reserves and in where each is listed. Both publish reserve reports with different detail and different levels of outside checking, and both have faced criticism. For a casino payment the gap is narrower: the cashier must accept that exact coin on that exact network, and USDC sent where USDT is expected can be stranded.
How to buy USDT usually comes down to two routes. A regulated exchange is the first: the buyer opens an account, verifies identity and funds it by card or bank payment, then keeps the coins there or withdraws them to a personal wallet. The other route is a person to person deal inside the exchange, where the platform keeps the coins locked until the seller confirms the payment arrived. Such deals carry their own traps, from money that turns out to be stolen to counterparties who ask to finish the trade outside the platform, where no protection is left.
Yes, in part: during a crisis the price can slip below its intended level, and well known stablecoins have traded below it for hours or days.
Inside the platform the coins sit in escrow and disputes can be raised; a deal finished outside it has no protection at all.
A stable token earns nothing by itself, so a promise of high interest on it means high risk or, often, a scam.
Both are reserve backed stablecoins, but different companies issue them, disclose their reserves differently and list them in different places.
The same coin runs on several networks, and coins sent on a network the receiver does not support can be stranded.