What the idea is behind a quaternion and why do developers prefer them for graphical design?

Question

I have a high level understanding of the mathematics and concepts but I want a _true_ eli5.

In: 8

Answer 1

Rotations in 3D can be represented by certain matrices (usually 3×3), or by quaternions. The latter are usually much simpler to handle, as the multiplication rules are much simpler.

In the end, they are fully equivalent.