HTTP Request Header
HTTP Header is the header information . As it’s name represents “Header” , it is the information on top of the http request . This information is in the form of text record .
Client computer request for something from web server using any web browser or any other form . Then in back end client computer or client server send the header information to Web host or web server .
With this information HTTP header is also sent . The request header contains the type, version and capabilities of the browser that is making the request . Server read this header information and return the data which is compatible with web browser and compatible with current version .
One more example
In this example tectrick.org is responsive website . User type www.tectrick.org in web browser hit enter . Web browser is Google Chrome , Version is 1.0 (suppose) and device is Smartphone with 380px and 460px screen resolution .
Know the question is what contains in header information ?
In HTTP request header send the information to web server . Web server read this information and return the result . The result is location of tectrick.org on web server, Mobile friendly 380px and 460px resolution compatible version of website and which is also compatible with Google chrome .
In short Definition : Http request header contains the information which is used by web server to provide proper and device compatible results to client computer .