In the early days of web publishing, there were few options for styling text, and those that did exist were contained within the HTML itself. For the most part, designers were only able to change certain colors and fonts. At first we couldn’t even change the gray background color of the page. But gradually, as the web gained popularity, more and more people voiced an interest in having better control over the style of web pages.
It took some time after the initial HTML spec was approved for the W3C to also set up a group to oversee Cascading Style Sheets ( CSS ). The group spent time creating guidelines for web publishers, clarifying the relationship between HTML and CSS. To reiterate, the focus of HTML is on how to structure the content on the page, whereas CSS adds the style.
If we were to translate this into home construction, you might say HTML is used to build the walls, while CSS applies the paint and decoration. Both are uniquely important aspects of web publishing that work together to create the pages we design.