What is Response Header?

 Just after the Status Line, Headers are displayed. Just like a Request Header, Response Header also contains zero or more Header lines. However, it is very uncommon to have zero Headers in the response. Lines just after the Status Line and before the Response Body are all Response Headers lines. Headers are used to pass additional information to the Client.

Example of Response Header:

HTTP/1.1 200 OK
Access-Control-Allow-Headers: Origin, Content-Type, sessionToken, loginId
Access-Control-Allow-Methods: GET, POST, PUT
Access-Control-Allow-Origin: *
Content-Encoding: gzip
Content-Type: text/html; charset=UTF-8
Date: Tue, 17 Dec 2019 09:47:14 GMT
Server: nginx/1.10.3 (Ubuntu)
Content-Length: 220
Connection: keep-alive