Planting The Seed Phrase Some words are shorter than 4 letters, including the word “act”. Other words are for a longer period than 4 letters, such as “abstract”. 1 set of mnemonic may be used to generate numerous addresses. This process of making account was launched in BIP32 & BIP39 https://setbookmarks.com/story18674327/bip39-light-standard-detailed-notes-on-bip39-phrase