How does bootstrap introduce the Glyphicons font icon?

You originally wanted to introduce the Bootstrap Fonts folder to the CSS folder, but the icon still failed to display. (Want to know exactly where the problem is)

So use the link, so it can.

Take the following code as an example: (from www.runoob.com)

<! DOCTYPE html> <link rel= "stylesheet" href= "Http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css" > <span class= "Glyphicon glyphicon-music" ></span></p> <p>music icon as a link: <a href= "#" > <span class= "Glyphicon glyphic On-music "></span> </a> </p> <p>music icon on a button: <button t Ype= "button" class= "btn btn-default btn-sm" > <span class= "Glyphicon glyphicon-music" ></span> Musi C </button> </p> <p>music icon on a styled link button: <a href= "#" Class
      = "btn btn-info btn-lg" > <span class= "Glyphicon glyphicon-music" ></span> music </a> </p> </div> <script src= "Http://cdn.static.runoob.com/libs/jquery/2.1.1/jquery.min.js" >& lt;/script> <script src= "Http://cdn.static.runoob.com/libs/bootstrap/3.3.7/js/bootstrap.min.js" ></ Script> </body>  
(Available in: http://v3.bootcss.com/components/#glyphicons Find all bootstrap available glyphicons free icon)