Fontweight is how thick or thin the text is and this post demonstrates how it looks. This can be applied to any content by adding css selectors (ex: thinnest) and the text thickness; if available, will show.
font-weight 100
thinnest strong
font-weight 200
thinner strong
font-weight 300
thin strong
font-weight 400
fit strong
font-weight 500
thick strong
font-weight 600
semibold strong
font-weight 700
bold strong
font-weight 800
extrabold strong
font-weight 900
boldest strong