Thankfully, in 2012 the developer Pieter Wuille made the BIP32 specification at The bottom with the hierarchical deterministic wallets. With each other with it, Pieter made a mathematical function to make a grasp key from which to derive all other keys inside of a deterministic way. The usage of BIP44 https://socialicus.com/story4211082/5-essential-elements-for-bip39-explained