Does changing a "regular" font with font-weight in CSS make it actually bold? (i.e. another font file)?

Question

I am a web developer and I am working on a project which uses Quicksand Light/Regular/Bold as font. The web application's standard font is Quicksand regular but there is also text which is lighter and bolder. As a web developer I'd normally apply a simple CSS style like so: font-weight: bold; // or 400, 600, 800. Is this a valid trick to avoid setting the font to every single element which is not "regular"? If not, are there fonts which work like this? (i.e. modify them via CSS to obtain a different font)

Answer 1

No. It depends how you structure your CSS. You can structure your css for Paragraph, headings, and title, so each of these attributes have different font values.

If you want to use the values more than once in your website structures, you need to use Class.

To differentiate Fonts values and font-family within your CSS for any attributes, you can use different set of class or id.