Now that you know how to use client-side code for Dynamics 365 CE, it is very important to learn about writing server-side code for Dynamics 365 CE since we want to run some of the business logic over a server instead of a client. At the time of writing, we have the following options for writing server-side code:

• Organization service endpoints
• Web API endpoints

The first option is to use Organization service endpoints. Organization service endpoints have been used since Dynamics CRM 2011 and will be deprecated in some Dynamics 365 CE future releases. We can use Organization service SOAP endpoints in applications outside of Dynamics 365 CE to connect to customer data. As shown in the following screenshot, we have two endpoints available when navigating to Settings | Customizations | Developer Resources:

The Web API uses OData V4 and provides better compatibility with different languages. At the time of writing, we can use both endpoints to work with entity data and metadata. We are going to discuss the Organization service methods here. If you want to work with the Web API, you can refer to https://docs.microsoft.com/en-us/dynamics365/customer-engagement/developer/webapi/get-started-web-api.