The client in Dynamics 365 for Finance and Operations is an HTML web client that runs in major browsers such as Microsoft Edge, Safari, and Chrome. The move to a web client has created the following changes for client forms and controls:

• Form controls are split into logical and physical parts. The physical presentation of forms and controls is now HTML, JavaScript, and CSS that runs within the browser. The X++ logical API and related state run on the server.
• The logical and physical parts are kept in sync through service calls that communicate changes from each side.
• The server tier keeps the form state in memory while the form is open.

While a lot has changed regarding how forms and controls run, for developers, creating a new user interface or form is similar to Dynamics 365 for Finance and Operations. You continue to create forms, menu items, and menus to build a user interface. The form metadata continues to be used to define controls and application logic.

You create a form, add data sources, and design form layout by adding controls and add business logic by overriding the methods. A new extensible control framework has been added that lets you add additional controls.

The following section talks about some of these user interface development concepts for operations.