为什么一次请求会产生多个request 和connect

var http = require("http") var server = http.createServer(function(req, res) { res.end("Hello Node!"); }); server.on("connection", function(req, res) { console.log("connected"); }); server.on("request", function(req, res) { console.log("request"); }); server.listen(3000);

为啥当我在浏览器中输入http://localhost:3000/的时候，会产生多个request和connect