HTML and CSS Relationships

HTML is the structure of a website. Css is the styling or appearance. You use HTML to lay ou tth econtend. Then Css to position, sset the colors, typography, etc.

index.html

The reason why the homepage of every website is typially the file "index.html", is because every browser will look fo rth efile first. Your indext.html file must be all lowercase with no spaces, numbers, etc.