The Domain Model section of the main menu is where you set up your app's domain model elements:
Click an entry in the Domain Model section to take you to the corresponding build page:
Modules is where you define what your app's data records will look like, and add buttons for running UI flows.
Relations is where you create relations that let an app user see records from other modules related to the record being viewed.
Dropdowns is where you create dropdowns, named sets of static values. Dropdowns are commonly used to let an app user choose one or more values from a list.
Dependencies is where you create dependencies that show or hide parts of a module depending on the values of fields.