In June 2019, during Microsoft Business Application Summit , Microsoft introduced PowerApps Portals as a new capability coming to PowerApps.
Microsoft have announced Portals with General availability, a new capability of the Power Platform and a low-code Portal that allows you to extend Common Data Service (CDS) to external users. Currently, update is available in all commercial regions (and will be rolling out in Government clouds soon).
Watch a video on PowerApps Portals by Charles Lamanna, General Manager of Power Platform team in Microsoft, where he described the capabilities of Portals with CDS and integration with different Authentication providers like Facebook, Twitter, LinkedIn, Google, Microsoft, AzureAD etc.
With the introduction of PowerApps Portals, Microsoft are also merging the capabilities offered by Dynamics 365 Customer Engagement portals to ensure that all the Dynamics 365 Customer Engagement application portals gets the benefit of our simplified low code offering. These capabilities feature a revamped end-to-end experience for makers to quickly create a website and customize it with pages, layout, and content. Makers can reuse page designs through templates, add forms and views to display key data from Common Data Service, and publish to users.