The recovery seed phrase (or mnemonic phrase) is a sequence of 12 or 24 words in a specific order, generated when a wallet is created, from which all of that wallet's private keys are mathematically derived.
Why it's the most important thing to protect
Anyone who knows your seed phrase can recreate your entire wallet and move all your funds, without needing physical access to your device. At the same time, if you lose it and your device breaks or goes missing, there's no "technical support" that can recover it for you: the responsibility is entirely yours.
Basic best practices
- Never write it down or store it on a device connected to the internet (photos, notes, email).
- Keep it in physical form (paper, or engraved on metal) in a secure location, ideally with a copy stored in a second location.
- Be suspicious of any website, support agent, or person who asks for it: no legitimate service needs to know your seed phrase to "verify" your wallet.
Relationship to private keys
The seed phrase is the source from which all the private keys of a hot or cold wallet are derived: losing the seed phrase means losing control of all the funds associated with it.