BIP39 means Bitcoin Improvement Proposal 39. The words are chosen from a selected list of 2048 widespread English words which can be utilized to the produce a binary seed (your personal vital). Standard recovery phrases use a particular list of 2048 words following the BIP39 standard (Bitcoin Improvement Proposal 39). https://ledbookmark.com/story4432252/the-ultimate-guide-to-bip39-seed-phrase-github