BIP 39 (Mnemonic Phrases)

BIP 39 is the Bitcoin Improvement Proposal which introduced the standard of mnemonic phrases. Mnemonic phrases offer a standardized method for converting a seed into a series of 12-24 words. Thus, a mnemonic phrase is all that is needed to recover all private keys of a wallet. While BIP 39’s standard has been adopted by almost all popular Bitcoin wallets, it was never implemented into Bitcoin Core, and does have a few engineering drawbacks. However, there are no known security weaknesses to mnemonic phrases, and they serve as a convenient way to backup Bitcoin wallets.