What is a material, texture and normal map

OK. So to update my previous post:

  1. create first aid kit mesh
  2. apply a texture to the first aid kit
  3. apply a material to the first aid kit (if needed)
  4. use a normal map (if needed)

Is a texture used before applying a material, or the other way around?
Is a texture and material used at the same time to achieve a wanted look?
A normal map is only used if added detail is needed?