HTTP security headers are a security measure that allows your website’s server to prevent some common security threats before they can affect your website.
When a user visits your WordPress website, your web server sends an HTTP header response to their browser. This response tells browsers about error codes, cache control, and other statuses.
The normal header response issues a status called HTTP 200. After this, your website loads in the user’s browser. However, if your website is having difficulty, then your web server may send a different HTTP header.
For example, it may send a 500 internal server error or a not found 404 error code.
HTTP security headers are a subset of these headers. They are used to protect websites from common threats like click-jacking, cross-site scripting, brute force attacks, and more.