HTML里的标签怎么链接外部样式表
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title></title>
<link rel="stylesheet" type="text/css" href="">
</head>
<body>
</body>
</html>
这里的href""里是写文件路径地址吗?