Better understand material properties

Imagine a room you must decorate for a baby on the way:

Material:
The actual Wallpaper

UV map:
A plan of how the Wallpaper pattern should fit over the walls

Normal map:
The parts of the Wallpaper that stick out or recede
(Especially when viewed at an angle / from the side)

Texture map:
Brochure showing general patterns to be used in the design of the Wallpaper

Baking:
Painting fixed sun / lamp shadows on the walls instead of using real lights

Diffuse:
A layout of the types of colors to be used on the Wallpaper
(Might include all the textures too)

Light Map:
A photo of the light in the room to help you recreate that same light later on.

FBX:
File format like Docx to store models / exchange work between different apps.


UVmap: Think of a dressmaker that would put all single parts of a dress on a flat paper and paint some texture on it before he continues to put them together with some seams so it could be carried by a human (3D) afterwards. He can't paint on a 3D-paper that well. Even your (texture)images (*.bmp, *.png, *.tga) are all flat... but should be put on some 3D item afterwards. The UVmap tells which face of your 3D mesh could be found on which place of your flat 2D paper (image) afterwards. It does not matter if you take a 2D pen or 3D pen afterwards if you mapped your faces. Its like a map where to find the same face of your 3D world on your 2D world afterwards. If you paint a line of color on a face on your 3D mesh in your 3D app you would get a line on the exact same face on that flat 2D image afterwards. Or if you paint on the place of a face on your 2D image in a 2D paint program then you would see that paint on the same face of your 3D mesh afterwards.


Normal map:
Is some faked 3D depth on a flat 2D image. It's similar to a bumpmap that makes a 2D image look a bit more 3D with adding some shadows (while it still remains flat). But a normalmap does not only creates one static shadow like it's the case in a 2D paintbumpmap but gives the 3D app info where it should do that shading and offset realtime afterwards. In short you could use a normal map to create greater details without adding more polygons. For example you could create PC keyboard with just one scaled cube and all your keys still get shadows on it using normal map. However if you would get your camera too close to that "faked" keyboard you would see ... it's still just a cube and that shadowing is just some rendering effect.


Light map:
Is used at static objects. It's like a UVmap but this time you don't paint on it manually but the engine gets some fresh empty image to paint some color for lightning on it. Lightning usually is expensive. All those faces have to be calculated at your light sources. So it's not 100% perfect. Some objects in your game are moving a lot (so this recalculating have to be done realtime in a "quick" way to don't stop your game and usually there are some tradeoffs). Some objects never move (walls of buildings) so you have all time of the world to calculate some static lighting on it before the game starts. And thats where lightmaps come in. If it's a static light and a static wall you could precalculate how the lightning would look like... and since you do this rendering before you start the game you could get greater lightning details without sacrifying a lot of performace (in comparison to dynamic lights).