BIP39 means Bitcoin Enhancement Proposal 39. The words are chosen from a selected list of 2048 prevalent English words which may be accustomed to the make a binary seed (your non-public key). Standard recovery phrases use a specific list of 2048 words subsequent the BIP39 standard (Bitcoin Improvement Proposal 39). https://getsocialnetwork.com/story4344828/little-known-facts-about-bip39-seed-phrase-list