How do developers create characters without humanoids?

Recently I saw a video:

At some point in the video, the creator and another developer seem to talk about not using humanoids for NPCs and the player in general. Up until today I had no idea this was possible. My questions are how does this work and how do i make one?

More specifically, how can you handle animation playing without a humanoid?

You can and should play animations using AnimationControllers rather than humanoids.

For a non-Humanoid character, all you need is a root part. That’s the part you move and rotate; everything else (limbs, accessories) attaches to it. Any part can be the “root part”.

No, I understand that. Im referring to for even normal R6 Characters having the humanoid object which animates within them to be removed and replaced with what I believe theyre referring to as a module script.