BIP39 means Bitcoin Advancement Proposal 39. The words are chosen from a certain list of 2048 typical English words that may be accustomed to the make a binary seed (your non-public critical). This informative article explains BIP39, the standard that defines how seed phrases are created, and summarizes how BIP32 https://bookmarklayer.com/story18826070/fascination-about-invalid-bip39-phrase