Public Key
A key derived from your private key that others use to verify your signatures and that forms your address.
Every private key has a matching public key, computed from it with one-way math. You can publish the public key freely; no one can run the math backward to recover the private one. It's the basis for receiving funds and proving a signature is genuine.
In practice you rarely see the raw public key. Wallets hash and shorten it into an address, the shorter string you share to get paid. The public key still does the verifying work under the hood.
Related terms
The secret number that proves ownership of crypto and authorizes spending it; whoever holds it controls the funds.
AddressA short string of letters and numbers that identifies where crypto can be sent on a blockchain.
Public-Key CryptographyA system using a paired public and private key so anyone can verify a signature only the owner could make.
Digital SignatureA cryptographic proof that a specific keyholder authorized a message, and that it hasn't been altered since.