[asadkn]

The difference isn't as much as it used to be in terms of file-size optimization as woff2 is pretty much supported by all browsers and you don't have to serve anything else now. Except for CJK and Arabic fonts, which have to be split or their woff2 size would be a few MB - this is Progressive Font Enrichment [1].

However, once distinction is font hinting data [2]. Google Fonts serve different files based for Windows vs Mac. The windows variations have hinting included.

[1]: https://rwt.io/typography-tips/progressive-font-enrichment-r... [2]: https://www.typotheque.com/articles/hinting