How to make independent scrolling in blocks on the page?

Question

css

Interested in creating an independent vertical scroll on the page. An ideal example is vc.ru (content and live block).
And another question on the topic: how to create a block with limited scrolling and further "sticking" to the screen? Here is an example of vk.com, where you can endlessly rotate the user's wall, but at the same time, the left block with an avatar and other things has its own behavior.