How it works css font-weight values?

Question

I don\'t understand font-weight values. When I change it as bold , normal or 600+, also changing fonts. But change it as 100 to 500, doesn\'t change anything. Why have these

Answer 1

font-weight value changes the weight of font.

Normally all browser only.

font-weight:bold;

work properly.

100-500 font-weight not bold the font because its percentage of bolding the font is less than 50%.

and browser automatically change it into normal font not bold