RE: Custom Web portal using CRM Dynamics 365
Hi Bhakti,
Custom entities can be surfaced using Dynamics 365 Portals. While the out-of-the-box portals include functionality to interact with cases, opportunities, knowledge articles, etc, as well as some portals-specific entities like forums, ideas, etc, you are not required to use that functionality.
When you install Portals, a number of solutions will be included that contain custom entities required by the Portals to operation (like Web Site, Web Pages, Page Templates, etc). These are the foundation of Portals, including what is required for authentication and authorization. From their you can create Entity Lists, Entity Forms and Web Forms that point to custom entities you create.
If you don't intend on using of the of the out-of-the-box Entity Lists, Entity Forms or Web Forms, I'd recommend using the Custom Portal option when installing. This will give you the smallest footprint.
Nick