Bip 39 Bip Utils Some words are shorter than 4 letters, including the word “act”. Other words are longer than four letters, including “abstract”. A single set of mnemonic can be employed to create various addresses. This technique of creating account was introduced in BIP32 & BIP39 long time back. https://www.youtube.com/channel/UCUpxfyTJ0fb78SQ55hU6OCw