HTTP Server Headers are a hidden part of a webpage response which only a browser can see, and it shows nowhere when a user opens typically any website or webpage. HTTP Headers are a piece of code which tells the browser that what should be the behavior of the browser while opening the requested page. There are several HTTP Headers used for modifying the browser, and some of them are Access-Control-Allow-Origin, Access-Control-Max-Age, Age, Cache-Control, Content-Language, Content-Length, Content-Type, Expires, Location, Server, Set-Cookie, Transfer-Encoding, X-Frame-Options and many more. A browser may or may not send all the headers at once, and it depends on server configuration and the webmaster how and when they want to send a specific header depending on scenarios. For example, some times a webmaster wants to specify cache time for a specific page, and they pass the Expires Header which tells the browser to save the resource in the cache and does not every time request the resource from the web server on each request from the same user. In this way, the other HTTP headers also provide many modifications which a webmaster can make in user's browser regarding the webpage.