is css only used for styling and we have to use html and css every time? why can't we get desired things only using css?

Question

why?

Answer 1

Html is mark-up language and CSS is a stylesheet language. You can't write CSS without HTML tags.
However you can make a static webpage without CSS. So html is structure of web. You can say CSS is useless without HTML.

Answer 2

Yes, since css is not a real programing language it can only be used to modify html documents(hence it is called a complementary language to html), so without html, css is useless

Answer 3

you could say css "manipulates" the elements of a website in a stylistic way but those elements have to get created in html
without html there is nothing you can "manipulate" with css