People or Peoples?

People is plural form by itself (as I know it). Dictionaries say “peoples” mean people belonging to a particular place, country, or race, etc. But still, I don’t understand it. I use “people” all the time. What is difference between “people” and “peoples”? When to use which?

For example, Oxford advanced learner’s dictionary has an example.
the native peoples of Siberia
If I were to write the above example, I would use “people”.
the native people of Siberia
So, am I correct? If I am wrong, please explain.

Some people (here) use “peoples” to mean many people (plural). I feel it is wrong; just like using childrens in place of children, which is already a plural form.

Do you use “peoples”? Can you give few examples?