I'm implementing  google's font named Roboto in my site.
I need 2 types : bold and regular.

So I checked both types and pressed the download button :

But in the downloaded rar file I got ALL the font styles ( also ones which I didn't choose) :

Anyway I wanted to test the regular font : (the fonts are now in my site and not being loaded from google).
(I got those other extensions types (eot,woff,svg) using a font converter (http://www.font2web.com/))
So I did :
 <style type="text/css">
    @font-face {
    font-family: 'Roboto';
    src: url('/font-face/Regular/Roboto-Regular.eot'); /* IE9 Compat Modes */
    src: url('/font-face/Regular/Roboto-Regular.eot?#iefix') format('embedded-opentype'), /* IE6-IE8 */
         url('/font-face/Regular/Roboto-Regular.woff') format('woff'), /* Modern Browsers */
         url('/font-face/Regular/Roboto-Regular.ttf')  format('truetype'), /* Safari, Android, iOS */
         url('/font-face/Regular/Roboto-Regularo.svg#svgFontName') format('svg'); /* Legacy iOS */
    }
   body  { font-family: 'Roboto', sans-serif; }
    </style>
Question :
Let's say I want to apply a Roboto bold style to a div.
Should I do it like this :
 div  { 
       font-family: 'Roboto', sans-serif;
       font-weight:bold
      }
or should I do this ( start all over...)
@font-face {
    font-family: 'Roboto-bold';
    src: url('/font-face/Regular/Roboto-bold.eot'); /* IE9 Compat Modes */
    ...
    }
and then
 div  { font-family: 'Roboto-bold', sans-serif; }