HTML and CSS Reference
The <aside /> element can be used to represent content unrelated to the main
content of the web site, such as tweets, related links, tags, and navigation
elements. These normally appear to the left or right side of the document, as
shown in Figure 3-3.
Figure 3-3. Structure of a document with the <aside /> element (highlighted in gray)
We can make use of the aside element for mobile by hiding it based on the
screen size, and revealing it when a user clicks a button to show it. This design
pattern can be found on the facebook mobile web app, and will be explored in
more depth with the workshop in Chapter 4.
Listing 3-3 shows how the aside element should be used, and Listing 3-4 shows
how you might have written the same code in HTML4.