A to Z
This article is using the List template and is configured to show child articles only in a 4-column grid.
The List template has been employed here to implement an A to Z page. It has body text just like a Default but also displays a list of child articles in a 4-column grid. The ordering of the child articles has been set (somewhat understandably) to "Item Heading A-Z", and the maximum number of items per page has been set to 26 (since you would generally want to display the whole alphabet on one page).
For "Summary View" (where this article may appear as an item in another list) it has been set to display just the summary, as it makes little sense to show the first n listable items since they will always be the same. To see this in action simply visit this article's parent, Listing pages.
The child articles also use the List template, and represent a single letter of the alphabet. They are configured to display metadata articles only, and each relate a specific item of metadata that establishes a relationship with other articles. For more details, visit one of the "letter" child articles.
For more information please view our online documentation: List template.