All elements in HTML have a background layer that is transparent by default. We can fill this background layer with a color, as we have already seen. We can also fill the background with an image and CSS provides us with some useful background properties that we can use for this purpose.

So far, we have used the background color property to apply background color to elements, and in our header element we have set the background to have a cool shade of orange color using the background-color property.