This is the inner part of a DC motor, which is used for a toy car. Studying the internal structures of an object can help you understand how it works, so I often try this when it's possible. The problem is, there are actually many things that you cannot really comprehend how they work only by simply observing their internal structures. The smartphone is a good example for this. If you disassemble a smartphone, you'll most likely end up with finding several IC chips, whose functions are unknown unless you're already familiar with them. So, to make the most of studying the internal structures of an object, you should at least know the basics of the related engineering field. Furthermore, recent devices or gadgets are based more on software engineering than on hardware. This has made examining the internal structures of recent products even less effective.