Defines the weight of the text.
default font-weight: normal;
The text is in normal weight.
font-weight: bold;
The text becomes bold.
font-weight: 600;
You can use numeric values. They all correspond to a particular named weight:
If the font family doesn't provide the requested weight, it will use the closest available one.
font-weight: lighter;
You can use relative keywords: lighter or bolder. The browser will use the next available weight.