Aside

The aside element is for content that is related to the primary content of the webpage, but is not considered primary content itself.

We’ll move our three images into an aside:

<main>
  <section>
    <h2>Anatomy and Physiology</h2>
    <h3>Size</h3>
    <p>The largest living species of turtle (and fourth-largest reptile) is the leatherback turtle which can reach over 2.7 m (8 ft 10 in) in length and weigh over 500 kg (1,100 lb).</p>
    <h3>Shell</h3>
    <p>The shell of a turtle is unique among vertebrates and serves to protect the animal and provide shelter from the elements.</p>
  </section>
  <section>
    <h2>Behaviour</h2>
    <h3>Diet and Feeding</h3>
    <p>Most turtle species are opportunistic omnivores; land-dwelling species are more herbivorous and aquatic ones more carnivorous.</p>
    <p>Turtles generally eat their food in a straightforward way, though some species have special feeding techniques.</p>
  </section>
+  <aside>
    <img src="https://assets.codepen.io/5804361/turtle_1.jpg"/>
    <img src="https://assets.codepen.io/5804361/turtle_2.jpg"/>
    <img src="https://assets.codepen.io/5804361/turtle_3.jpg"/>
+  </aside>
</main>

The three images will have a lighter background than the main and be on the right.

Here’s our page so far:

Screenshot of page with images on the right.