In layman's terms, what does it mean when you retopologize something?
TL;DRRetopologizing means rebuilding a huge high-poly sculpt as a low-poly mesh that can run in game, tracing its shape and silhouette with as few polys as possible while still animating well.
Just building a mesh that can actually go in the game. Because the high polys can be several million, tens of millions of polys, and that can never go in.
So essentially you freeze your mesh. You have your high poly, then you decimate it and then bring it into your retopology tool and then start tracing over it with polys and try to recreate the same exact shape with the least amount of polys as possible, yet enough for animation to still be able to move it around. And like Corey mentions in the video, about having to keep the silhouette and making sure that no matter what angle you look at that thing in a 3D space, it will always create the exact same silhouette. That way the character doesn't get lost in the translation between the high and the low.
I would have assumed you guys would have said the high poly phase because you get to make such detail. It seems like you're attracted to the challenge of going, all right, we got this really pretty thing that looks awesome, a lot of polys, will never work in-game, but now we get to put it in-game.
Yeah, there's two aspects. There's the making it as good as you want it to be, and then there's the ability to get it in the game to mimic how great your original source looked.