Hey kiddo, have you ever played with blocks before? You know how you can build towers and houses with lots of different blocks? Well, a system of systems is kind of like that!
Imagine each block is like a different system - one block might be a system for sending emails, another block might be a system for taking pictures with your phone, and yet another could be a system for playing games.
Now, if we put all of these systems together, it becomes a system of systems! It's like a big tower made up of lots of smaller towers.
But the thing is, each system is really important on its own too. You need the email system to send messages, the camera system to take pictures, and the game system to have fun! If one of the systems doesn't work properly, the whole system of systems can be affected.
So, a system of systems is when lots of important systems work together to make something even bigger and better. And it's really important to make sure all the individual systems are working properly so the whole thing can keep working smoothly.