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 applies.
What are stablecoins? They are crypto tokens designed to keep a fixed value against an outside asset, usually one unit of a traditional currency. The most widely used stablecoins, USDT and USDC among them, are backed by reserves that a company holds. Others are backed by other crypto locked as collateral, and some, called algorithmic stablecoins, try to hold their value through code alone. Several algorithmic coins have collapsed completely in the past, so the kind of backing tells a reader most of what could go wrong.