link元素 rel src href属性

The SRC and HREF attributes are used to include some external entities like an image, a CSS file, a HTML file, any other web page or a JavaScript file.

Is there a clear differentiation between SRC and HREF? Where or when to use SRC or HREF? I think they can't be used interchangeably

To refer a CSS file: href="cssfile.css" inside the link tag.
To refer a JS file: src="myscript.js" inside the script tag.
To refer an image file: src="mypic.jpg" inside an image tag.
To refer another webpage: href="http://www.webpage.com" inside an anchor tag.

rel 属性规定当前文档与被链接文档之间的关系。

只有 rel 属性的 "stylesheet" 值(文档的外部样式表)得到了所有浏览器的支持。其他值只得到了部分地支持。