TLS (Transport Layer Security) is the protocol that encrypts data between your browser and a web server. You see it in action whenever a URL starts with https://. SSL (Secure Sockets Layer) was its predecessor — the terms are often used interchangeably, but modern sites use TLS 1.2 or TLS 1.3.
How TLS Handshake Works
When you connect to an HTTPS site, your browser and the server perform a TLS handshake: they agree on an encryption method, the server presents its certificate, and a session key is generated. All subsequent data is encrypted with that key.
Why TLS Matters for SEO and Security
Google uses HTTPS as a ranking signal. Browsers mark HTTP sites as “Not Secure.” Check your certificate status with our SSL Checker tool, or return to the protocols overview.