I've been asked this several times, so I'll answer here.
An airdrop is when a project distributes tokens for free to eligible addresses, often to reward early users and spread token ownership more widely.
To claim a legitimate airdrop, you only need to use your wallet to initiate the claim transaction. You may sometimes need to pay a small amount of gas, but you should never be asked for your recovery phrase or private key.
$UNI is the token distributed in that famous airdrop in 2020. It's currently at 6.978.
Have you misunderstood this before too?

#UNI

I'm not guaranteeing this is correct—use your own judgment.