Bip39 Binary Lookup Table Some words are shorter than 4 letters, like the word “act”. Other words are for a longer period than 4 letters, which include “summary”. 1 list of mnemonic may be used to develop many addresses. This process of producing account was introduced in BIP32 & BIP39 https://peakbookmarks.com/story18637530/seed-phrase-generator-checker-detailed-notes-on-seed-phrase-generator