Thankfully, in 2012 the developer Pieter Wuille created the BIP32 specification at The bottom of the hierarchical deterministic wallets. Collectively with it, Pieter created a mathematical operate to produce a master crucial from which to derive all other keys inside of a deterministic way. This text explains BIP39, the standard https://socialinplace.com/story4229957/a-review-of-bip39