Krylov–Bogolyubov theorem

Krylov-Bogolyubov theorem is a way of understanding how systems change and evolve over time. It states that if you take a system, like an electric circuit, and make it do something, like turn on a light, then the system will continue to do that same thing over and over. So if you turn the light on and then leave it, it will stay on forever. This is because the system is self-sustaining, meaning it is able to keep itself going without any extra help. This is different from a system that needs regular maintenance or energy to keep it running.