BIP39 means Bitcoin Enhancement Proposal 39. The words are picked from a selected list of 2048 prevalent English words which may be accustomed to the deliver a binary seed (your non-public critical). Standard recovery phrases use a specific list of 2048 words following the BIP39 standard (Bitcoin Advancement Proposal 39). https://thebookmarkid.com/story19562235/how-much-you-need-to-expect-you-ll-pay-for-a-good-bip39-definition