We've learned a bit about HTML. While HTML does a great job of puting words and picture on the page, CSS exists to make your content look good.
Let's take a look at a rather simple example of what CSS does. Go ahead and flip between the HTML and CSS tabs of the CodePen below. You'll see the HTML sections has just a simple header: <h1>This Is My Header</h1>. The text turns up red though. How is that possible? The magic of CSS is how. Click on the CSS tab. You'll notice we set the color to red with this line: color: red. If you change the red to green what happens? It turns green! BOOM You just wrote your first CSS. Congrats!
Now that you understand the basics of CSS, continue onto the next lesson and get a deeper understanding of CSS.