Header Origin vs Host
cross-domain, header
Solution
The Host is the domain the request is being sent to. This header was introduced so hosting sites could include multiple domains on a single IP.
The Origin header is the domain the request originates from.
The Host header is always included. The Origin header is included sometimes: It is always included on cross-origin requests (across all browsers), and in Chrome/Safari, it is also included on same-origin PUT/POST/DELETE requests. Same-origin GET requests do not include an Origin header.
Problem
I have a question about the working of the Origin and Host HTTP headers. I have an Ajax page "Page A" which will call the Ajax feed "Page B". I saw that the request header of "Page B" from the Ajax call contains the headers: ``` Origin: http://example.com Host: example.com ``` However, if I call the "Page B" directly, the request header will only contain the `Host` header: ``` Host: example.com ``` Thus, I want to know what is the difference between the `Origin` and `Host` headers, and why they show up on non-direct calls? Can Origin be prepended and passed to server?