Content Pages are new in Liferay DXP 7.1. They provide a way to create pages with inline content. Traditionally in Liferay, all content has lived outside the page, to be added to any page as needed. With Content Pages, you can create a design on a page and then edit text or images directly within the page without any abstraction between the page and the content.
The process starts with a design. After the design is completed, a developer creates Fragments based on those designs. Widgets can be embedded in Fragments. Fragments can then be converted into Page Templates. Developers can define areas of Fragments to have editable text or images, allowing changes during the final publication process for the page.
This means that Fragments can be created as completely static elements to be used to build a Content Page, or marketers and content creators can customize them, using the Fragment as a tool for creating beautiful content.