HTTP Strict Transport Security (HSTS) is a web security feature that forces web browsers to always use an encrypted (HTTPS) connection for a specific domain or subdomain. HSTS helps to prevent man-in-the-middle attacks, where an attacker intercepts network traffic and can read, modify or inject data. By implementing HSTS, a website can ensure that users are always connecting securely and that their sensitive information, such as login credentials or financial data, is protected from prying eyes. Once a browser has seen an HSTS header for a domain, it will always connect to the domain via HTTPS in future, even if the user types in http:// instead of https://.
