Below is a Page List Block, it is used to display pages from your Sitemap. For example these are two pages that are sub pages, or child pages, of Programs.

Page lists are used to offer a menu of pages, often these blocks serve to offer access to sub/child pages, which you do not show in your main navigation to keep it clean and simple. Notice these pages are NOT being displayed in the main navigation as Third Level items, instead visitors accessing the Programs page are offered the Page List to navigate deeper into specific program pages.

This is a page description, which can display in Page List blocks along with a Page Thumbnail. Access this page's setting (the Gear) and edit the Description and Thumbnail.
This is a page description, which can display in Page List blocks along with a Page Thumbnail. Access this page's setting (the Gear) and edit the Description and Thumbnail.