BIP39 stands for Bitcoin Improvement Proposal 39. The words are picked from a specific list of 2048 typical English words which may be accustomed to the deliver a binary seed (your non-public critical). This text explains BIP39, the standard that defines how seed phrases are made, and summarizes how BIP32 https://socialmediatotal.com/story4065827/the-invalid-bip39-phrase-diaries