Modern pages are a foundational component of the SharePoint Modern Experience first introduced in SharePoint Online and SharePoint 2019 on-premises. Modern Pages are designed to be faster to build and be automatically responsive to all device screen sizes without additional effort. When you create a page, you can add and customize web parts, and then publish your page with just a click.
Modern pages provide a fast, easy way to build responsive pages using the functionality of modern web parts. Pages are similar to classic web part pages and publishing pages, but are less structured and easier to create.
Using Modern pages is a great way to share ideas using images, Excel, Word and PowerPoint documents, video, and more. You can create and publish Modern pages quickly and easily, and they look great on any device.