Normal maps are a better type of bump map, that creates an illusion of depth detail on an surface. This is entirely faked, the actual mesh is not physically effected by it. A normal map uses RGB information to correspond with X, Y, and Z axis, and are used to make details like dents and holes in models. It is like contouring for 3D models. It is better for things like rotation and is also useful for meshes that need to deform with animation.
One of the older types of map. Like normal maps, they are used to make the illusion of depth, however they do this with a greyscale image that limits to 8-bit colour information. The values are used for either up or down, whiter colours are above the surface and darker colours are below the surface, where as grey is anywhere between.
Displacement maps physically displace the mesh when applied. The pull and distort parts of the actual mesh to change it. The mesh needs to be subdivided or tessellated so that real geometry is created, and it is similar to a bump map in that it uses greyscale colours to do this.
I then tried to make my own normal map for a cube. I made a low poly cube that was close to the overall shape I wanted, and automatically UV unwrapped it. I then duplicated it and made a higher poly version. I used booleans to make and add bolts to it, and I beveled the edges so that they would be picked up and look better. I then started to bake it, and this is where everything went wrong. I’m not sure why, but black lines appeared around the seams of the cube. I tried lots of different things, I stitched together some of the UVs, I tried geometry normals instead of surface normals, and nothing would fix it. After I tried to sew together some of the UVS, the black lines just went insane and somehow looked even worse, and just wouldn’t fix regardless of how many settings I changed or how many times I baked it. So, in my own time I plan to try this technique again so that I have something good for this post. I will post it in an update so that I don’t lose this mistake, because mistakes are important to keep for personal growth.