The question of the use shaders

Unity Engine
1

Good morning people.

As we say, I am getting the experience. In this regard, there is a question in the definition of the technologies (shaders).

Here are links to two videos.

And the question of what shaders are used in the video for the formation of the day and night. I have yet to mind the only Atmospheric Scattering. But maybe I missed something.

2

Lighting is calculated with shaders, so everything that is rendered in that game uses a shader. Every triangle on screen.