What is the initial step in creating a custom module in Sitefinity?

The initial step in creating a custom module in Sitefinity is defining data structures. This foundational step is crucial because it involves outlining the shape and type of data that your module will manage. Defining data structures includes creating the relevant content types, fields, and relationships between these types, which provide the backbone for all subsequent development work.

Once the data structures are defined, you can proceed to create a user interface to allow users to interact with this data. Implementing business logic is also important, but it comes after understanding what data you will be working with. Setting up security roles is typically a later stage in the development process, focused on access control and permissions within the module. Therefore, starting with a solid definition of data structures ensures that all further development steps can effectively leverage the data your module will handle.