A Common Data Service entity contains not just the entity definition, but also the required fields, views, forms, relationships, business rules, and charts. The fields and forms and so on are sub-components and belong to the entity.
In earlier versions of Dynamics 365, adding an entity included all the sub-components in your solution. You couldn't have a solution just containing the individual sub-component you needed to change. Because of the way unmanaged solutions work, it was easy to accidentally release changes that had been made to other sub-components by other users.
In the Power Platform, you can create a solution that only contains the selected sub-components of an entity. This reduces the risk of accidentally including changes that have been made in another solution.
When you add an existing entity to a solution, you will be presented with a page similar to the following:
In the preceding...