what is the character of \r\n\r\n in nodejs TCP/IP

i'm having a problem when i send data to client using TCP server in node js. this is my code

var net = require('net');

var server = net.createServer(function (socket) {
    // We have a connection - a socket object is assigned to the connection automatically
    console.log('CONNECTED: ' + socket.remoteAddress +':'+ socket.remotePort);

    socket.on('data', function(data) {    
        var datas = JSON.parse(data);
        console.log('DATA ' + socket.remoteAddress + ': ' + data);    
        //socket.write("kenapa ya / HTTP/1.0\r\n\r\n");
    }).on('connect', function() {
        // Manually write an HTTP request.
        var data = {
        "name" : "test",
        "args" : {
            "data":[{
                "a":1
            }]
            }
        };
        socket.setEncoding("utf8");
        socket.write(JSON.stringify(data) + "\r\n\r\n");

    }).on('end', function() {
        console.log('DONE');
    });


});

server.listen(1337, '127.0.0.1');
console.log("server is listen on 1337");

actually that code is work in my client socket, but when i'm try to socket.write(JSON.stringify(data)); without \r\n\r\n too long response from server and i cannot get the message from server.

anyone know what happen? and what the effect this code \r\n\r\n? i'm using php to create socket client.