So like if I have a wall with some objects in front of it...does each texel on the wall have a 2D shadow map array? Or does each texel just have a single float?
I think a texture stores the shadow of a particular light source. It's like you are viewing the scene from the point of view of the light source. A wall doesn't have a texture. If the program want to render the wall, it will project it to the shadow texture of the light source and look up the shadow value.