Okay kiddo, have you ever watched a pot of water boil on the stove? Imagine if you could take a snapshot of the water every second to see how it's changing - that's kind of what scientists and engineers do when they're trying to study something that changes over time. They take pictures, or "snapshots," at different moments to see how things are changing.
Now let's say you're trying to study something that changes really quickly, like water that's boiling really violently. Taking a snapshot every second might be too slow - you'd miss a lot of changes that happen in between each snapshot. So what can you do? You could take snapshots faster, maybe every half-second or quarter-second, but that would be a lot of work and you might still miss some important changes.
That's where the Krylov-Bogoliubov averaging method comes in. It's a way for scientists and engineers to study things that change quickly without having to take pictures every moment. Instead, they take pictures at regular intervals (like every 10 seconds) and then use math to estimate what things look like in between those snapshots.
It's kind of like if you took a bunch of pictures of your dog running around the park, but you didn't want to take a picture every second because it would be too many pictures. So instead, you take a picture every 5 seconds and then use your memory, or imagination, to fill in what your dog looked like in between those pictures.
The Krylov-Bogoliubov averaging method uses a special kind of math called linear algebra to estimate what things look like in between snapshots. It's named after two really smart guys who came up with the idea - Nikolay Bogoliubov and the scientist Krylov.
Overall, the Krylov-Bogoliubov averaging method is a useful way for scientists and engineers to study things that change quickly without having to take pictures every moment. It saves time and makes it easier to understand how things change over time.