TL;DR
SSL/TLS is the encryption technology that powers HTTPS. It creates a secure, encrypted connection between a user's browser and your server. TLS (Transport Layer Security) is the modern version. SSL is the old name that stuck around. When you see the lock icon in your browser, TLS is working. Modern websites use TLS 1.2 or 1.3 for secure connections.
The Simple Explanation
When you visit a website over HTTPS, a "handshake" happens between your browser and the server. They agree on encryption methods and exchange keys. After that, all data is encrypted so no one in between can read it.
SSL vs TLS
| Version | Status | Should You Use It? |
|---|---|---|
| SSL 2.0 | Deprecated 2011 | No, vulnerable |
| SSL 3.0 | Deprecated 2015 | No, vulnerable |
| TLS 1.0 | Deprecated 2020 | No, weak |
| TLS 1.1 | Deprecated 2020 | No, weak |
| TLS 1.2 | Active | Yes, widely supported |
| TLS 1.3 | Active (newest) | Yes, best option |
What SSL Certificates Do
An SSL certificate serves two purposes:
- Encryption: Enables secure data transfer
- Identity: Proves the server is who it claims to be
Certificate Types
- Domain Validation (DV): Proves you control the domain. Fast, free from Let's Encrypt.
- Organization Validation (OV): Verifies the organization exists. Takes longer.
- Extended Validation (EV): Extensive verification. Shows company name in some browsers.
Getting SSL/TLS Certificates
Most hosting platforms handle certificates automatically:
- Vercel: Automatic, free
- Netlify: Automatic, free
- Cloudflare: Automatic, free
- Let's Encrypt: Free, requires setup (often automated by hosting)
What is the difference between SSL and TLS?
SSL (Secure Sockets Layer) was the original protocol, but it's outdated and insecure. TLS (Transport Layer Security) is the modern replacement. When people say SSL, they usually mean TLS. Modern websites should use TLS 1.2 or 1.3. SSL versions are deprecated and should not be used.
What is an SSL certificate?
An SSL certificate is a digital document that proves a website's identity and enables encryption. It contains the domain name, organization info, and a public key used for encryption. Certificates are issued by Certificate Authorities (CAs) like Let's Encrypt, DigiCert, or Comodo.
Are free SSL certificates as secure as paid ones?
Yes. Free certificates from Let's Encrypt provide the same encryption strength as paid certificates. The difference is in validation level and warranty. For most websites, Let's Encrypt certificates are perfectly suitable. Paid certificates may offer extended validation (EV) or organization validation (OV) for businesses that want the extra verification.