Good source for learning about light/shadow/gradients in flat designs

I came across this creation here on dribble.

I have marked some areas with arrows, which are either 'lit up' because of bright light, or have 'shadows' because of absence.

And also this one here :

This also has some sort of gradient/similar shades of a color being used to show depth/shadows etc.

I find these really fascinating. This adds a very rich feeling to the item drawn in the scene.

Q1. Does this have a typical name in graphic design world ? Lights and Shadows or something ? Is this style called something particular ? Its very difficult to search about it without a concrete name.

Q2. Is there some tutorial I can look up to understand how to imagine about these shadows/lights/gradient. (I want to learn it in general, not specific about these particular illustration or tool).