Explain about sending a request to the server in ajax

Explain about sending a request to the server in ajax
To send a request to the server we should use the open () and send () method. Open() method has three arguments of which the first one defines which method to use which would help in sending the request. The second argument explains about the URL of the server side script. The third argument or request determines how the request should be handled whether asynchronously or not. Send () method is useful to send a request to the server to determine functionality.