HTML (Hypertext Markup Language) and CSS (Cascading Style Sheets) are two of the core technologies for building web pages.
HTML is used to create the structure of a web page, such as headers, paragraphs, links, and images. It uses tags to markup content, telling the browser what type of content it is dealing with (such as a heading, a paragraph, or a table).
CSS, on the other hand, is used to control the look and feel of the web pages that HTML structures. It dictates the layout, colors, fonts, and other visual aspects of a web page. CSS provides the stylistic features of the website.
So, HTML is all about structure and semantics, while CSS is about presentation and style. They both work together to create web pages as we know them. You can’t really build a web page with only one of them.
While HTML can have style information included within it, modern best practices generally encourage keeping the HTML (content) and CSS (presentation) separate. This makes both the HTML and CSS easier to maintain (because there is a clear separation of responsibilities), and makes it easier to apply consistent style rules across an entire website.