Passphrases

In plain words

A passphrase is an extra word or sentence you add to your seed phrase. Seed plus passphrase opens one wallet; seed alone — or seed plus any other passphrase — opens a completely different one. There is no "wrong passphrase" error: every guess opens a valid, probably empty, wallet. That is the power and the danger. A thief with your seed finds nothing. And if you forget the passphrase, the coins exist, visible, and permanently out of reach.

Why it matters

• Protection if your seed backup is found — paper alone no longer spends.
• Plausible deniability: the bare seed can hold a decoy wallet.
• It is a second single point of failure. Forgetting it is final.

Not to be confused with

• PIN — unlocks a device and can be reset. A passphrase derives the wallet; nothing resets it.

Go deeper

• BIP 39 — where seed phrases and passphrases are specified.
• Seed phrase
• Seed backups