Why does the font on the site “soap” (you can see blur, fuzziness)?

Question

css

Greetings, tell me why sometimes when you connect a font to a site, it seems to be a little blurry, especially if you assign the bold style. How to fight, what fonts should be used?

Answer 1

The font may not have a bold (or for example 500, 600, etc.) style and the browser will try to come up with it on its own. The end result is soap.