A collection of random words generated during wallet creation that lets you get back into your crypto wallet if you lose access or delete it. Knowing your seed phrase ultimately gives you access to your private key, which verifies your ownership of your cryptocurrency. Anyone who knows your seed phrase can use it to make a copy of your wallet and add it to their own device. Once that happens, they can empty all of your funds from your wallet
Example
“After her phone was stolen, she recovered all her crypto assets by entering her 12-word seed phrase into a new wallet app on her replacement device.”