I assume you are wondering why he is multiplying by 1,1,0 vector.

vector1 * vector2 works like this: x1*x2, y1*y2, z1*z2

so when he multiplies any vector by 1,1,0

it will nullify Z value (ie snap to ground plane)

This trick is also great for making square grid of meshes:

get integers out of forloop indexes: “nth loop on X” and “nth loop on Y”. Make those 2 into vector, lets call it “index_Vector”

Make vector with sizes on x, y, y for mesh (or spaces in square grid you are making) call it “spacing_Vector”

then:

“index_vector” * “spacing vector” will give you nice grid locations.

much less connections than calculating all values separately.