In HTTP messages, the content describes the 'information' conveyed in the message body (which follows the header section), after any message framing from HTTP/1.1 chunked transfer Encoding has been removed.
This was referred to as a "payload" in HTTP/1.1, but message "content" distinguishes from frame payloads in HTTP/2 and HTTP/3 where the data in a single frame could be header data, body data, or other control information....1 chunked transfer encoding has been removed. This was...HTTP/1.1 response, transfer encoding encodes the data into chunks....