Accelerated Mobile Pages (AMP) is an open source initiative that Google is pushing to provide faster-loading content on mobile devices.
For WordPress, Automattic has created an AMP plugin that will render a WordPress blog posts in AMP (the plugin does not currently support pages and archives).
The plugin essentially dynamically generates an AMP version of a given blog post as long the requestor adds /amp/ to the end of the url. So, for example, https://brian.carnell.com/articles/2016/orcus/ will give the full HTML version of one of my blog posts, while https://brian.carnell.com/articles/2016/orcus/amp/ will return the AMP version.
At some point, Google seems likely to penalize pages that are not AMP-enabled as the search engine company increasingly sees mobile as key to its future. Plus, AMP is a much better alternative IMO to competing initiative such as Facebook’s Instant Articles.