How to define service classes on CodeIgniter 3

Question

When writing an application in the Java framework, we define entities, services, and controllers likewise patterns. Following that pattern, how do you write an application in the CodeIgniter 3 framework?

The controller is there, and we can consider models as entities, but how to define services in the framework? Since following OOP in the applications, it is necessary to represent entities(models) as separate classes. Am I planning to follow the below-mentioned architecture.

Answer 1

For this, it is possible to define a separate package as a service and create all service layer-related classes in that package. After that, importing the written classes where needed makes it possible to work as required(Model-Service-Controller).