HTTP request header is the information, in the form of a text record, that a user’s browser sends to a Web server containing the details of what the browser wants and will accept back from the server. The request header also contains the type, version and capabilities of the browser that is making the request so that server returns compatible data.
Upon receipt of the request header, the server will return an HTTP response header to the client that is attached to the file(s) being sent.
