In this section, we will provide details about the Dynamics 365 CE application architecture, along with all of the possible extension points that can be used for extending the capabilities of Dynamics 365 CE. The following screenshot shows the application architecture of Dynamics 365 CE:

As discussed previously, we can use different clients to access a Dynamics 365 CE application. We can write different client-side extensions such as a JavaScript library, HTML web resources, custom apps, and SiteMap extensions. We can use the Dynamics 365 CE Web API and web service to integrate both on-premises and Azure applications. We can use the Web API and web service out of the box, or we can write our own extensions for integration. 

We can write different server-side extensions using plugins and custom workflows that extend the capabilities of out-of-the-box workflows. We can write sync or async plugins in Dynamics 365 CE that can interact with both custom and system business entities. We will be discussing these in more detail in Chapter 7, Extending Dynamics 365 CE.

Dynamics 365 CE has two databases: config and organization databases. The config database is used to store configuration information about Dynamics 365 CE, whereas the organization database is used to store customer data for entities such as accounts, contacts, and so on. Dynamics 365 CE contains a special type of view that is known as filtered views; we use these to develop reports for Dynamics 365 CE. Filtered views allow the user to access data based on their security roles. We will be discussing these reports in more detail in Chapter 9, Business Intelligence and Reporting. If we are working with Dynamics 365 CE on-premises, two SQL Server databases are created; but if we are using Dynamics 365 CE Online, an Azure database will be used for our Dynamics 365 CE subscription.