Now to answer the question of what CSS does. It's simple: while HTML structures the content on a page, CSS allows you to format it to make it more appealing to the reader. Originally, web developers used only HTML - that was in the early days of Internet technology. With the help of markup was possible to highlight a paragraph, and the title, and change the shape of the text. And that's all it took. Working in a writing company and every day receiving a request on our site https://writemypapers4me.net/ someone to write my paper, I was it all at the beginning incomprehensible, but I think so if a person has set a goal to understand something - then you need to achieve their goals. Over time, these features are not enough - and there was a technology formatting without changing the content itself and the structure of the document. CSS solved the problem of "zoo" of formatting tags when different browsers supported different tags. Their unification and common base simplified the work with web documents and made life easier for webmasters.