Forbidden archeology is a fancy way of saying that there are some things that people have found which don't fit with what we already believe about history. It's like finding a piece of a puzzle that doesn't seem to fit with the picture on the box. Some people believe these findings could change our understanding of history, while others think they might just be mistakes.
For example, some people have found tools and artifacts that are way older than the oldest things we thought humans could make. This can make scientists scratch their heads, because it doesn't fit with what they thought they knew. Maybe they weren't made by humans, or maybe humans were more clever than we first thought? These are the kind of questions scientists are trying to answer through forbidden archeology.
But not everyone agrees with the idea of forbidden archeology. Some people think that these findings are just made up, or that they don't actually contradict what we know about history. It's a bit like a big debate between grownups trying to figure out whether those puzzle pieces really belong in the same box.
So the idea of forbidden archeology is basically a big discussion among grown-ups about whether or not we should change what we believe about history based on new discoveries.