To undertand the HttpKernel first we need to understand how the web page works over the server.
Every HTTP web interaction begins with a request and ends with a response.
for this we require server and browser.
Generally developer make a request (create PHP code)(e.g. the URL) in a browser;
The browser sends a request to the server;
The server sends back the
to the browser;
The browser displays the resource to the user.
Generally developer make a request (create PHP code)(e.g. the URL) and returns a response (e.g. an HTML page or JSON string).