BIP39 means Bitcoin Improvement Proposal 39. The words are selected from a certain list of 2048 prevalent English words which can be used to the produce a binary seed (your personal key). In case you are unsure about a certain word's spelling, utilize the search operate (Ctrl+File on Windows/Command+F on https://fatallisto.com/story8664450/getting-my-bip39-words-to-numbers-to-work