A section is like a container with extra spacing above and below it.
<div class="section">
<p>This is a section with some extra space at the top and bottom.</p>
</div><div class="section-small">
<p>This is a section with some extra space at the top and bottom.</p>
</div><div class="section-large">
<p>This is a section with some extra space at the top and bottom.</p>
</div><div class="section-large-x">
<p>This is a section with some extra space at the top and bottom.</p>
</div><div class="section-large-xx">
<p>This is a section with some extra space at the top and bottom.</p>
</div>