TREZOR - a physical hardware Wallet, independent of the Internet. It contains your secret keys, and the device "knows how" to sign transactions without connecting to the Internet. Even being an autonomous "cold" storage, the hardware Wallet is flexible when performing tasks - both offline and online. With it you can already spend bitcoins at any time. It can be attached to a key chain or worn in a pocket. As you can see, TREZOR allows you to store bitcoins off the network, and when you connect it to the computer, you send the necessary transaction.