How does USDT or Chainlink bridging work?

I understand how wrapping works, like wrapped BTC: you just store it in a vault on its original blockchain through a counterparty and then that counterparty mints a wrapped token designed to be a representation of that token on a desired blockchain which you can later redeem for your original token in its original blockchain. But what about tokens like USDT or Chainlink? They are on Eteherum and Polygon and Solana and many others. Are they wrapped tokens? And how do they bridge exactly? How does their bridging works?

Thank you for the answers in advance! Hope you have a good day!