Bip39 Seed. A BIP39 mnemonic sentence is a list of words (most often 12 or 24) that we are able to communicate with a lot more correctly than other people that are not words (bits and numbers along with the like). BIP39's purpose in introducing the use of mnemonic words https://directoryserp.com/listings13162886/bip39-word-list-numbers-https-linktr-ee-bip39-not-known-details-about-bip39-online