SSL

SSL stands for Secure Sockets Layer: the technology that encrypts traffic between a visitor’s browser and a website. Today the protocol in use is actually TLS (Transport Layer Security), but people still say “SSL certificate” in everyday talk.

An SSL/TLS certificate proves the site is who it claims to be and enables HTTPS — the padlock in the address bar. Without it, passwords, forms, and payment data travel in ways that are easier to intercept. Browsers warn on insecure pages, and search engines favor secure sites.

A real-life example of SSL

Sending a postcard vs. a sealed envelope: anyone along the route can read the postcard. SSL/TLS seals the envelope so only the intended recipient can open it. For a shop checkout or a login form, that seal is non-negotiable.

Certificates often come free (Let’s Encrypt) or via your hosting / CDN provider and must be renewed or auto-renewed. For security basics that include SSL, see Web Wise: How Can I Keep My Website Secure?.