A public key is a cryptographic code paired with a private key. These keys work together to let you receive and send cryptocurrency transactions.
Any user can have information about your public key, using it to send payment to you via a blockchain network. However, you can access the received funds only if you have a private key with you to unlock these funds.
A public key can also be considered an address where senders can transfer crypto payments to you. Each transaction made on a blockchain is cryptographically secured or encrypted using the public key.
The decryption of this transaction requires a private key. The public key is also used to verify the transaction's authenticity.