Luckily, in 2012 the developer Pieter Wuille made the BIP32 specification at The bottom in the hierarchical deterministic wallets. Alongside one another with it, Pieter produced a mathematical function to produce a master important from which to derive all other keys in a very deterministic way. This post describes BIP39, https://socialbuzztoday.com/story4195947/5-simple-techniques-for-bip39-word-list-pdf