An alphanumeric string which is publicly known, and which is hashed with another privately held string to sign a digital communication. In the case of Bitcoin, the public key is a Bitcoin address. A long string of letters and numbers which marks a location on the blockchain where bitcoins can be stored. The public key, or its QR code , can be freely shared.
Malone, J.A (2015). Glossary of Bitcoin Terms and Definitions. United States: Lulu Press, Inc