SSL (Secure Sockets Layer) is a security protocol that provides encryption and authentication for data transmitted over the internet. It works by establishing a secure connection between two points on the internet, usually a web server and a web browser. The connection is established by a process called SSL handshake. During the handshake, the two parties exchange information about their encryption keys, authentication methods, and other security parameters. Once the handshake is complete, the data is encrypted and transmitted securely between the two points.
For example, when a user visits a website, the browser will establish a secure connection with the server by initiating an SSL handshake. The server will then authenticate itself to the browser using an SSL certificate, and the browser will verify that the certificate is valid. After the handshake is complete, the browser and server will exchange encrypted data, ensuring that the data is safe from interception or tampering.