Extended data types (EDTs) and base enumerations (enums) are data types that are created and managed in the development environment. Base enums represent a list of literals, while EDTs are reusable data types that have a specific definition. The Application Object Tree (AOT) in finance and operations apps contains many existing EDTs and base enums that can be extended for use in your project, or you can create new data types. This module will focus on creating new data types.