What types of HTTP headers do you know?

• General Headers: These relate to both the request and the response, but not to the message body.

  • Cache-Control
  • Connection
  • Date
  • Pragma
  • Trailer
  • Transfer-Encoding
  • Upgrade
  • Via
  • Warning

• Request Headers: Contain more information about the resource to be fetched or about the client.

  • Accept
  • Accept-Charset
  • Accept-Encoding
  • Accept-Language
  • Authorization
  • Expect
  • From
  • Host
  • If-Match
  • If-Modified-Since
  • If-None-Match
  • If-Range
  • If-Unmodified-Since
  • Max-Forwards
  • Proxy-Authorization
  • Range
  • Referer
  • TE
  • User-Agent

• Response Headers: Contain additional information about the response, such as its location, server information.

  • Accept-Ranges
  • Age
  • ETag
  • Location
  • Proxy-Authenticate
  • Retry-After
  • Server
  • Vary
  • WWW-Authenticate

• Entity Headers: Relate to the message body of the request or response.

  • Allow
  • Content-Encoding
  • Content-Language
  • Content-Length
  • Content-Location
  • Content-MD5
  • Content-Range
  • Content-Type
  • Expires
  • Last-Modified
  • Extension-header (custom, non-standard)

This classification is according to RFC 2616. In newer standards (RFC 7230-7235), the classification may differ slightly.