Okay, kiddo, an operating system is like the boss of your computer or phone. Your computer or phone has lots of parts like a screen, a keyboard, a mouse, and a hard drive. The operating system helps all these parts work together.
It's like when you play with toy blocks. You have to stack them in a certain way so they won't fall down, right? That's what the operating system does, it makes sure all the parts in your computer or phone work together so they don't make any mistakes or fall apart.
The operating system also helps you control what your computer or phone does. You can open apps or programs, watch videos, listen to music, or write a document. The operating system helps you do all these things easily and quickly.
So, just like a boss in a company, a good operating system helps your computer or phone run smoothly and efficiently. And that, my dear, is what an operating system is!