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/when to use SRC or HREF? I think they can't be used interchangeably. I'm giving below few examples where these attributes are used: 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