HTTP Headers

HTTP headers are key-value pairs of metadata sent in HTTP requests and responses, by both the client (such as your web browser) and the server (such as the AMI's nginx install). This metadata provides essential information about the connection, helping the client & server sync up for data transfer.

HTTP headers are processed by the client application and the web server, and are usually invisible to the end user. Data sent as HTTP headers includes, but is not limited to:

• How information sent through the connection is encoded.
• Compatibility & version information about the client & server
• Cache control
• Session verification & authentication
• Remote access policies

• Mozilla Development Network article about HTTP headers
• List of HTTP header fields on Wikipedia
• GeeksforGeeks tutorial about HTTP headers
• RFC 9110 for HTTP semantics
• HTTP Headers Guide from the OWASP Cheat Sheet Series