Bip39 Checksum. Now, at another level we use these acquiring and alter key bunch to create specific private keys. Use the above mentioned make private keys and chain code and move them to the above mentioned talked about operate kchild = kpar + hash(Kpar, cpar, i) to produce unique keys. https://cheapbookmarking.com/story18957171/bip-39-https-linktr-ee-bip39-bip39-generator-an-overview