Meta descriptions in Google search results help give searchers a sense for what’s going to be on the page. Programmers can customize this meta description on every page. Sometimes, Google creates their own for your page, based on the keyword which populates your site on their search results. But now, for sites that are list pages, List Snippets will now replace this meta description information.
If the search result contains a structured list, for instance a table or a large series of bullets, Google will select three relevant rows or items and include that information within a bulleted format on the search results page itself. Google has been experimenting with this content area in other ways recently. Their announcement of rich snippets for music allows Webmasters to display the song info within this meta description space.