Devlog#2: Woah!! 3D Graphics!

This week for Intermediate Game Development...A Crash Course Video
Questions this week: 

• Why do we rely on triangles instead of quads (squares) in 3D graphics?
• What’s the difference between Painter’s Algorithm vs Z-Buffer?
• What is the surface normal of the floor in Vector3 notation? What is the surface normal of your face?
• Pick a part of the video where you thought either "wow that makes so much sense" or "wtf is that, why would you do that?"

As someone who's been starting off all my 3D objects in Blender with cubes, it's interesting to see that triangles are what's relied on rather than quads, but it makes sense. As the video says, having three points in a 3D space gives only one possible answer for where to render a plane instead of a bajillion different answers. Even when it comes to occlusion, the method for doing so is meant to be simplistic. The Painter's Algorithm goes in order from back to front like a painter would when working on a landscape, while the Z-Buffer doesn't order the objects and uses their Z axis to figure out which spaces are visible for each object.

To be honest, I'm pretty confused what a surface normal is , but according to what I've researched this vector should be perpendicular to the surface at a given point. The floor is horizontally flat so I'd assume the surface normal would be (0,1,0) while for my face, if it were a low poly circle, it'd perhaps be (0,0,1).