What are SSL? TLS? SSL/TLS? HTTPS?

• SSL
• TLS
• HTTPS

When using SSL certificates, you will often encounter terms such as SSL, TLS, SSL/TLS, and HTTPS. What do they stand for? And what is the relationship between them?

Let's Encrypt major changes countdown: TLS/SSL certificate validity reduced to 45 days, domain verification window shortened to 7 hours.

• Let's Encrypt
• TLS/SSL certificate
• 45 days

On December 2, 2025, Let’s Encrypt announced that it will further shorten the validity period of its publicly trusted TLS/SSL certificates from the current 90 days to 45 days by 2028. At the same time, the authorization reuse period for domain name verification will be shortened from the current 30 days to 7 hours.