When we say "initial uniform structure," it means starting with everything looking the same. Imagine you and your friends all wearing the same outfit, like a school uniform. That's a uniform structure.
In science or math, we use this idea to talk about how things start out. For example, if we're looking at a big group of things - let's say stars in a galaxy - we might say they all started out looking the same. That's the initial uniform structure. But over time, things might change. Some stars might get bigger or smaller, and they'll start to look different from each other.
So, initial uniform structure means everything starts the same, but over time things can change and become different.