Seed Phrase / Mnemonic Phrase
A seed phrase is a list of 12 or 24 ordinary words that encodes the master key from which all your wallet’s keys are derived.
In depth
Instead of backing up dozens of private keys, you back up one phrase that can recreate them all. The words come from a fixed list of 2048, so the phrase is easy to write down but astronomically hard to guess. Anyone with the phrase has your entire wallet — treat it like the cash itself.
Why it matters
Your seed phrase is the single point of recovery — and the single point of failure.