A secret recovery phrases, also known as a seed phrase or a mnemonic phrase, is a set of words (usually 12 or 24) that can be used to derive private keys.
Private keys are also known as spend keys, and they do just what they sound like - allow you to spend your funds.
Every non-custodial wallet, including MetaMask, will provide you with the secret recovery phrase to that wallet.
The secret recovery phrase how you can always access your funds.
If you lose your device, or forget your password, as long as you have access to your secret recovery phrase, you will still have access to your funds.
It's very important that you don't share this secret recovery phrase with anyone. If anyone asks you for it, they are most likely trying to steal your funds.
For more security tips, you can visit: Top 10 tips to keep your crypto and NFTs safe.