What is a ball mill ? its working principle?

Описание: Do you still remember this tool?
In our memory,
Every summer when our family eats noodles,
we always use it to smash some garlic juice on the surface,
Sometimes when we buy medicine at the pharmacy,
We will also meet this,
put some pills in a tool,
Then hit it hard a few times,
To get the powdered medicine.
Of course this is from big to small,
not only in daily life,
It is also very common in modern industry.

It's a ball mill,
1. industry ball mill
https://www.staurk.com/product/50.html
2.rod mill
https://www.staurk.com/product/127.html
3.ceramic ball mill
https://www.staurk.com/product/128.html
4.6 types lab ball mill
https://www.staurk.com/product/148.html
5.cone ball mill
https://www.staurk.com/product/149.html