Example Concept: HTTP security headers provide an additional layer of security by instructing the browser on how to behave when handling web content. Key headers include Content-Security-Policy to prevent cross-site scripting, Strict-Transport-Security to enforce HTTPS, X-Content-Type-Options to prevent MIME type sniffing, X-Frame-Options to mitigate clickjacking, and X-XSS-Protection to enable the browser's built-in XSS filter.