BIP39 stands for Bitcoin Improvement Proposal 39. The words are selected from a specific list of 2048 typical English words which can be used to the make a binary seed (your personal crucial). This additional complexity boosts the chance of misplacing the passphrase, and so shedding your copyright. According to https://socialrator.com/story9739212/5-simple-techniques-for-bip39-word-list-pdf