Transport Layer Security (TLS) and Secure Sockets Layer (SSL) are cryptographic protocols that provide secure communication over the Internet. TLS/SSL enables server authentication, encryption of data, and integrity of data transmitted between a client and server. The TLS/SSL handshake process establishes an encrypted connection between a client and server by agreeing on encryption algorithms and exchanging certificates to authenticate both ends. Once the handshake is complete, encrypted messages are sent between the client and server to securely transmit sensitive data like credit card information.