The video tutorial explains how to create a service to retrieve posts for a specific user from a database. It covers setting up a GET request, handling user not found exceptions, and avoiding recursive loops during JSON conversion. The tutorial also demonstrates testing the service with various scenarios, including users with and without posts, and non-existent users.

Describe the issue that arises when trying to retrieve user details along with post details.

What happens when a request is made for a non-existing user?