As a Hexagonal Close Packing lattice, which is the correct way to represent the maximum density arrangement of equal spheres.

If you've seen a stack of spheres, with the bottom layer in rows offset by one radius such that each sphere touches six others at the same height, and the next layer nestled in the intersections of this bottom layer, that's a hexagonal close packing.

Also, the "hexagons are the bestagons" attitude generalizes to three dimensions by dismissing face-centered cubic packing as an inferior way to look at the arrangement.

To generalize the Youtube video aspect, see also this Matt Parker/Steve Mould video on spherical packing: https://www.youtube.com/watch?v=3inLMXcetUA