Content - HTML
The aim of design is to enhance the presentation of the content! Content is the most important element of a website.
You should spend time gathering your content, thinking about your layout, and sketching your ideas on paper
Presentation - CSS
Styling content will go a long way, for websites we use Cascading Style Sheets (CSS).
CSS is a set of rules that allow you to style content. The rules are element:style pairs, which identify the element and how it is to be styled.