BIP39 stands for Bitcoin Enhancement Proposal 39. The words are picked from a certain list of 2048 typical English words that may be used to the crank out a binary seed (your private critical). Standard recovery phrases use a particular list of 2048 words following the BIP39 standard (Bitcoin Improvement https://nowbookmarks.com/story18884946/5-simple-techniques-for-bip39-word-list-pdf