scratch the surface (of something)
idiomPart ofscratch
scratch the surface (of something) — idiom
1. To only begin to deal with or understand a small part of a larger issue or topic
1.idiom
Definition
To only begin to deal with or understand a small part of a larger issue or topic.
Example
The report only scratched the surface of the pollution problem.
In our short visit, we just scratched the surface of Tokyo's culture.