CSS is an abbreviation for cascading style sheets.

the Modern Style Language is used to design documents written in a variety of computer languages, including HTML, stylistic rules known as style sheets are used to present content in structural documents, such as (colors, fonts, and layout), and style sheet languages ​​are mostly used in the context of visual presentation rather than  spelling.  and quotation  marks. 

CSS developed by World Wide Web Consortium ( W3C). The initial release was more than 24 years ago, and the latest release was more than 5 years ago. The type of format is style sheet language and CSS is the container for style rules for HTML elements and it designed to separate between presentation and content .

The goal is: to increase the accessibility, clarity, and ease of visual presentation. It provides flexibility and control over display properties. Enable web pages to share formatting by defining related CSS Reducing complexity and redundancy ability to render the same markup page with different styles for different views.

all style sheet language offer functionality in these areas such as  syntax in order to be expressed in a machine readable manner, and selectors specify which elements are to be influenced by the style rule, and properties that can be given values to change one aspect of rendering an element..., and values and units,  and formatting model...

Some limitations of the current capabilities of CSS include:

1 selectors are enable to ascend

2 cannot explicitly declare a new scope independent of position

3 cannot name a rule

4 cannot include style from one rule into another rule 

5 cannot target specific text without modifying  markup

former issues:

1 vertical control limitation

2 absence of expressions

3 lack of column declaration

advantages:

1 separation of content from presentation.

2 site-wide consistency

3 bandwidth

4 page formatting

5 accessibility

HTML is hypertext markup language , developed by WHATWG.  The initial release  was 28 years ago , and the latest release is a living standard (2021)  the type of format ( document file format ), HTML is a container for html elements and is contained by web browsers.

HTML is the standard markup language for documents designed for presentation on the web. HTML describes the structure of a web page. CSS can help style and include references to the appearance of a document. It also provides a means for creating structured documents by referring to the structural semantics of text (title/paragraphs/links..) are specified.  HTML elements are represented by written tags such as ( <input/> ) or (<p>) These tags provide information about the document text. HTML tags are not displayed in browsers but are used to understand the content.