The good thing is, in 2012 the developer Pieter Wuille made the BIP32 specification at the base from the hierarchical deterministic wallets. Collectively with it, Pieter made a mathematical purpose to produce a learn critical from which to derive all other keys in a very deterministic way. Mnemonic words illustrations http://josueaqpi312.huicopper.com/from-words-to-riches-just-how-to-successfully-make-use-of-bip39-passphrases-for-your-copyright-budgets