Importance of package

Api.kt

package api


// since the class is declared as internal, it is accessible to all the packages 
// that are declared inside the same module.
internal class ApiClient

client.kt

package service

import api.ApiClient

class Service {
  
  val client = ApiClient()
  
  // we were able to access internal class ApiClient inside this class because 
  // the file Api.kt is present inside a package named api
  
  // therefore with help of import keyword we were able to access 
  // the file, class or top level members from another package and reuse it 
}