HTTPS is an extension of HTTP that ensures secure data transfer over the web using encryption protocols like TLS or SSL. It's vital for websites handling sensitive information, signified by a padlock icon in the browser's address bar.

HTTPS is properly configured When HTTPS is set up correctly, it ensures secure communication between a website and its visitors. This is achieved through the use of a valid SSL/TLS certificate, which encrypts data exchanged between the user's browser and the server. Security headers like Content Security Policy (CSP) and HTTP Strict Transport Security (HSTS) are in place to enhance protection against cyber threats. All resources on the website are loaded securely over HTTPS, preventing mixed content issues. This not only improves security but also boosts the website's SEO ranking and builds trust with users, as indicated by the padlock icon in the browser's address bar.