Public Key Encryption is a type of encryption using different keys for encryption than for decryption. The set of associated keys used for these operations are known as an AsymmetricKeyPair consisting of of PublicKey and a PrivateKey.
The PublicKey is published, and used to decrypt messages from or to encrypt messages to the holder of the PrivateKey. It can also be used to confirm a DigitalSignature generated with using the complementary PrivateKey.
Contrast with SymmetricCipher
It is an element of PublicKeyInfrastructure