BIP39 stands for Bitcoin Advancement Proposal 39. The words are picked from a particular list of 2048 frequent English words which can be used to the produce a binary seed (your private key). Standard recovery phrases use a certain list of 2048 words adhering to the BIP39 standard (Bitcoin Improvement https://bookmarkmiracle.com/story20570511/helping-the-others-realize-the-advantages-of-bip39-mnemonic-phrase-tool