How do data processing approaches differ in View and in the application layer?

In the application layer (for example, ViewModel or Model), data processing and preparation occur: loading, parsing, business logic, formatting. Here, data is transformed into a model suitable for display.

In the View (presentation), data is only displayed and responds to user actions. The View should not contain complex data processing logic to maintain separation of concerns and simplify maintenance.

For example, a ViewModel can convert a date into a string with the required format, and the View simply displays this string in a UILabel. This approach improves testability and the structure of the application.