SSL vs TLS — What's the Difference?
SSL (Secure Sockets Layer) was the original protocol developed by Netscape in 1995. TLS (Transport Layer Security) is its modern successor, with TLS 1.3 being the current standard. Despite SSL being deprecated, the term "SSL certificate" persists colloquially when referring to TLS certificates.
How TLS Works
TLS uses asymmetric encryption during the handshake to securely exchange a symmetric session key. All subsequent communication is encrypted with that session key. This combines the security of asymmetric encryption with the performance of symmetric encryption.
Types of SSL Certificates
DV (Domain Validation) certificates verify domain ownership — issued in minutes. OV (Organisation Validation) also verifies the legal identity of the organisation. EV (Extended Validation) requires the most verification and was traditionally shown with a green address bar.
Why HTTPS Is Non-Negotiable
Chrome marks HTTP sites as "Not Secure". Google uses HTTPS as a ranking signal. HTTP/2 and HTTP/3, which dramatically improve performance, require HTTPS. Free certificates are available from Let's Encrypt — there is no excuse for running HTTP in production.
