Generally, when you are modelling objects for a game, one of the priority is to keep the number of polygons as low as possible. The mesh was pretty good but we want to optimize it further.
Here above the textured model.
Here above the optimized “low-poly” version of it
The two meshes differ not to much but each polygon subtract from the original mesh is a bit of time the engine can assign for doing something else or keep the frame rate a bit higher.
Personally I hate the UVW beacuse are a tedious work but you have to make them…
Now comes the fun, bake the texture and the detail in the normal map.