Definition
A series of 12 or 24 words generated by a cryptocurrency wallet that serves as a master backup. Anyone with access to the seed phrase has complete control over the associated wallet and funds.
Why It Matters
Your seed phrase is the single most important piece of information in cryptocurrency security. Losing it means losing access to your funds permanently. Sharing it means losing everything.
Example
When setting up a new Ledger hardware wallet, the device generates a 24-word seed phrase that must be written down and stored securely offline.
Related Terms
Wallet
Cold Wallet
Hot Wallet