BIP39 means Bitcoin Advancement Proposal 39. The words are picked from a selected list of 2048 typical English words which may be accustomed to the crank out a binary seed (your non-public vital). Standard recovery phrases use a selected list of 2048 words following the BIP39 standard (Bitcoin Improvement Proposal https://wakelet.com/wake/XIloocQnhZGti1r1O9tJb