What are security headers, and which ones should I implement to enhance my application's security?

In simple terms, security headers are HTTP response headers that, when properly configured, can significantly enhance the security of your web application. Key headers to implement include:

• `Content-Security-Policy` to prevent cross-site scripting and data injection attacks.
• `Strict-Transport-Security` to enforce secure HTTPS connections.
• `X-Content-Type-Options` to prevent MIME type sniffing.
• `X-Frame-Options` to protect against clickjacking.
• `Referrer-Policy` to control the amount of referral information sent with requests.

So, implement these headers in your web server configuration or web application framework to significantly bolster your app's security posture.