is node js create server every http request?

i am now studying node js and am very confused how servers work in node js

i searched in google and youtube but i still didn't get it.

http.createServer(function(req,res){
    res.writeHead(200,{'Content-Type':'text/plain'});
    res.write("siodjfiusd <br> so8dzyfs8d79fh")
    res.end();
}).listen(8765);

i learned that how we make http server but how actually it works ?

via Mr Leo