BIP39 stands for Bitcoin Improvement Proposal 39. The words are selected from a particular list of 2048 prevalent English words which may be used to the produce a binary seed (your non-public important). This extra complexity improves the risk of misplacing the passphrase, and so shedding your copyright. BIP44: Whilst https://kingslists.com/story20048967/bip39-phrase-generator-can-be-fun-for-anyone