<script charset="utf-8" src="http://g.tbcdn.cn/kissy/k/1.3.1/??node-min.js,dom/base-min.js,event/dom/base-min.js,event/base-min.js,event/dom/focusin-min.js,anim-min.js,event/custom-min.js,switchable-min.js,cookie-min.js,ajax-min.js,json-min.js,xtemplate/facade-min.js,xtemplate/runtime-min.js,xtemplate/compiler-min.js?t=20130815000847.js" async=""></script>
<link rel="stylesheet" href="http://g.tbcdn.cn/??tb/conve/0.0.5/common-min.css,tcc/tbr/1.0.21/tbr/common.css,tcc/tbr/1.0.18/tbr/widget/phone/phone.css,tcc/tbr/1.0.18/tbr/widget/game/new-service.css,tcc/tbr/1.0.18/tbr/widget/game/game.css,tcc/tbr/1.0.18/tbr/widget/card/card.css,tcc/tbr/1.0.18/tbr/widget/qq/qq.css,tcc/tbr/1.0.18/tbr/widget/game/game-all.css,tcc/tbr/1.0.18/tbr/widget/yeyougame/yeyougame.css,tb/ticket/1.0.2/convenience/css/index-min.css,trip/marketing/0.0.5/trip-min.css,tbc/search-suggest/1.0.11/new_suggest-min.css?t=20130625">
这是从淘宝首页截取的两段代码，一个src里写了好几个js文件并用逗号隔开，这么做的好处是什么，这么多文件可以一次都请求下来吗，减少http请求吗，原理是什么？？？