BIP39 stands for Bitcoin Improvement Proposal 39. It outlines a method for creating a mnemonic phrase, which is a series of words that serve as a human-readable representation of a wallet’s seed key. Generally, a mnemonic phrase consists of 12 to 24 words. These words are randomly generated from a list of 2048 options.

The use of these phrases makes it easier to back up and restore wallets, as remembering a series of complex alphanumeric characters can be challenging. When generating a wallet, the mnemonic phrase enables users to derive all the private keys associated with that wallet.

This means that by simply writing down the phrase, users can regain access to their funds even if they lose their device. BIP39 improves user experience by providing a more accessible way to manage keys while maintaining the security that cryptography offers. As long as the phrase is kept safe, the associated wallet will remain secure. This approach is widely adopted in various wallet software and hardware solutions.