SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are the cryptographic protocols that encrypt communication between the visitor's browser and the web server. When a website uses HTTPS, it is using TLS (although it is still colloquially called SSL).
The SSL certificate is the file that authenticates the server's identity and activates encryption. Without it, data travels in plain text and can be intercepted.
Why does it matter?
- Protects sensitive data (passwords, payment data, forms).
- Activates the security padlock in the browser.
- Is a ranking factor in Google.
- Prevents browsers from showing "not secure site" warnings.
Bacan includes free SSL with Let's Encrypt in all hosting plans.
See also: SSL Guide at Bacan, HTTPS.