The data relationship between two entities in the system referred as Entity relationships. In CRM, an user needs to setup relationships, as Dynamics 365 platform is built on a relational database. And CRM customization tools make it easy to create custom entities with no programming experience, but establishing relationships must be understood if the custom and system entities are to work together.
Field defines the individual data items that can be used to store data in an entity. Fields are sometimes called attributes by developers. In solution explorer, customization tools are used to edit system fields that allows customization, and to create or edit a custom field.
Dynamics 365 users, especially the sales team will be much relieved with the new enhancement in duplicate detection as part of Dynamics 365 Release Wave 2 update. The new enhancement allows Dynamics 365 users to merge duplicate records (accounts, contacts and leads) so that the most current information entered by the user could be merged with one of the duplicate records detected. By this, users need not manually merge records or visit a record to make additional data entry.