The box model in CSS describes the boxes which are being generated for HTML-elements. The box model also contains detailed options regarding adjusting margin, border, padding and content for each element. The diagram below shows how the box model is constructed:
The box model in CSS
The illustration above might seem pretty theoretical to look at, so let's try to use the model in an actual case with a headline and some text. The HTML for our example is (from the Universal Declaration of Human Rights):
<h1>Article 1:</h1>
<p>All human beings are born free
and equal in dignity and rights.
They are endowed with reason and conscience
and should act towards one another in a
spirit of brotherhood</p>
By adding some color and font-information the example could be presented as follows:
The example contains two elements:
<h1> and <p>. The box model for the two elements can be illustrated as follows:
Even though it may look a bit complicated, the illustration shows how each HTML-element is surrounded by boxes. Boxes which we can adjust using CSS.
The properties which regulate the different boxes are:
padding, margin and border.