BIP39 means Bitcoin Advancement Proposal 39. The words are chosen from a selected list of 2048 frequent English words which can be accustomed to the generate a binary seed (your personal vital). Standard recovery phrases use a selected list of 2048 words adhering to the BIP39 standard (Bitcoin Enhancement Proposal https://onelifesocial.com/story4154105/the-greatest-guide-to-seed-phrase-bip39