Nanotopography is like a tiny world that exists on really, really small surfaces that we can't see with our eyes. It's like looking at a map of a city, but this city is so small that it wouldn't even fit on a piece of paper. Everything in nanotopography is made up of really tiny bumps, holes, or shapes that are smaller than a hair on your head.
Scientists study nanotopography because it can be used to help make things work better. For example, they might use nanotopography to make a surface really smooth so things can slide across it easily, or they might use it to add little bumps that help cells in our bodies grow better. Basically, different types of nanotopography can be used to make different things do different jobs better!
But because nanotopography is so small, scientists need special tools and machines to study it. They use things like microscopes that can magnify things millions of times bigger so they can see the tiny bumps and shapes up close.
In summary, nanotopography is a world made up of really tiny bumps, holes, and shapes that you can’t see with your eyes. Scientists use special tools to study it to help make things work better.