Webapi Resolving Ajax cross-domain request issues

Webapi Adding these sentences to the configuration file will solve the problem of browser cross-domain request invocation? Why is it?

<system.webServer> <validation validateintegratedmodeconfiguration="false"/> <modules runallmanagedmodulesforallrequests="true"/> "Access-control-allow-origin"Value="*"/> <add name="access-control-allow-headers"Value="Content-type"/> <add name="Access-control-allow-methods"Value="GET, POST, PUT, DELETE, OPTIONS"/> </customHeaders> 
This is the browser security-based considerations, when cross-domain requests, when the browser receives a response message, only the file header message contains the Access-control-allow-origin property in order to process the message body data.
Webapi Resolving Ajax cross-domain request issues