Is it me? or my browser? (firefox) or my system? (Mageia with autohinting enabled), but I do not see any difference between the fonts on this site and the woff

Is it me? or my browser? (firefox) or my system? (Mageia with autohinting enabled), but I do not see any difference between the fonts on this site and the woff files I use myself in several projects. I am a critical type user as I use design programs like illustrator and indesign for on paper designs. Can somebody show me the difference?