What is asymmetric encryption?

There are two sides in an encrypted communication: the sender, who encrypts the data, and the recipient, who decrypts it. As the name implies, asymmetric encryption is different on each side; the sender and the recipient use two different keys. Asymmetric encryption, also known as public key encryption, uses a public key-private key pairing: data encrypted with the private key can only be decrypted with the public key, and vice versa.
TLS (or SSL), the protocol that makes HTTPS possible, relies on asymmetric encryption. A client will obtain a website's public key from that website's TLS certificate (or SSL certificate) and use that to initiate secure communication. The website keeps the private key secret.
TLS (or SSL), the protocol that makes HTTPS possible, relies on asymmetric encryption. A client will obtain a website's public key from that website's TLS certificate (or SSL certificate) and use that to initiate secure communication. The website keeps the private key secret.