Entity headers are HTTP headers that provide information about the body of a message. They can appear in both requests and responses, describing properties of the content such as type, length, encoding, or last modification date.
1. Content-Type
Content-Type: application/json; charset=UTF-82. Content-Length
Content-Length: 10243. Content-Encoding
Content-Encoding: gzip4. Content-Language
Content-Language: de-DE5. Cache-Location
Content-Location: /files/document.pdf6. Last-Modified
Last-Modified: Tue, 30 Jan 2025 14:20:00 GMT7. ETag
ETag: "abc123xyz"8. Expires
Expires: Fri, 02 Feb 2025 12:00:00 GMT9. Allow
Allow: GET, POST, HEAD10. Refresh (Not standardized but often used)
Refresh: 10; url=https://example.comThese headers help describe the content of an HTTP message, optimize caching strategies, and ensure correct rendering.
Response headers are HTTP headers sent from the server to the client. They contain information about the server’s response, such as status codes, content types, security policies, or caching rules.
1. Server
Server: Apache/2.4.41 (Ubuntu)2. Date
Date: Wed, 31 Jan 2025 12:34:56 GMT3. Content-Type
Content-Type: text/html; charset=UTF-84. Content-Length
Content-Length: 34565. Cache-Control
Cache-Control: max-age=3600, must-revalidate6. Set-Cookie
Set-Cookie: sessionId=abc123; Path=/; Secure; HttpOnly7. ETag
ETag: "5d8c72a5f8d9f"8. Location
Location: https://www.new-url.com/9. Access-Control-Allow-Origin
Access-Control-Allow-Origin: *10. Strict-Transport-Security (HSTS)
Strict-Transport-Security: max-age=31536000; includeSubDomainsResponse headers help the client interpret the received response correctly, enforce security measures, and optimize caching strategies.
Docker
