An asymmetric key is a type of cryptographic key used in encryption and decryption processes. Unlike symmetric keys, which use the same key for both operations, asymmetric keys come in pairs: a public key and a private key. The public key can be shared openly, while the private key is kept secret. This system allows secure communication, as only the holder of the private key can decrypt messages encrypted with the corresponding public key. Asymmetric key cryptography is fundamental to various security protocols, including SSL/TLS for secure web browsing and PGP for email encryption. It ensures that sensitive information remains confidential and is only accessible to authorized users. This method enhances security in digital communications and transactions.