what is roboto bold css in web page dsign code example

Example: font roboto css

@font-face {
    font-family: 'Roboto';
    src: url('Roboto-ThinItalic-webfont.eot');
    src: url('Roboto-ThinItalic-webfont.eot?#iefix') format('embedded-opentype'),
         url('Roboto-ThinItalic-webfont.woff') format('woff'),
         url('Roboto-ThinItalic-webfont.ttf') format('truetype'),
         url('Roboto-ThinItalic-webfont.svg#RobotoThinItalic') format('svg'); (under the Apache Software License). 
    font-weight: 200;
    font-style: italic;
}