Okay kiddo, have you ever needed help from a grown-up or a teacher because you didn't know how to do something by yourself? Just like that, service systems are also like grown-ups who help you when you need something or want to learn something new.
So, let's imagine you are at a restaurant, and you want to order some yummy food. When the waiter comes to your table, he is providing a service to you by taking your order and bringing your food to your table. This is an example of a service system.
A service system can also be a little more complicated. It's like a team of grown-ups working together to make sure you have everything you need. For example, when you go to the doctor or a hospital, you need medical help, but you also need someone to schedule your appointment, someone to give you directions to the right area, and someone to help you fill out forms.
In the same way, when you go to a store, you need someone to help you find what you're looking for, someone to answer your questions, someone to ring up your purchases, and someone to wrap them up so you can take them home.
So, a service system has many pieces that work together to help you get what you need or want. Pretty neat, huh?