A Lightning page is a custom LAYOUT that you may use to create PAGES for the Salesforce mobile app or Lightning EXPERIENCE. Lightning pages are a cross between Visualforce pages and page layouts. Lightning pages, like page layouts, allow you to add custom items to a page. Instead of being fields or Visualforce components, these elements are Lightning components, which provide far more freedom. A Lightning page's structure changes depending on the device it's being viewed on. When you create a page, the template you choose determines how it appears on different devices. The template for the Lightning page divides the page into regions.

Lightning pages are made up of Lightning components, which are small, reusable, and adjustable pieces that you can drag and drop into page regions in the Lightning App Builder. A Lightning page can be used to CONSTRUCT an app page that you can add to the NAVIGATION bar of a Lightning app, making it visible in both Lightning Experience and the Salesforce mobile apps. An app page allows users to quickly access the most important objects and items in the app.