Bip39 Passphrase. A BIP39 mnemonic sentence is usually a set of words (most often 12 or 24) that we can easily communicate with much more properly than other characters that are not words (bits and numbers as well as the like). BIP39's intent in introducing the usage of mnemonic words https://phase2directory.com/listings13029805/bip39-mnemonic-https-linktr-ee-bip39-bip39-options