Generalizing the obvious

• Texture mapping is a way of adding surface details to 3d models; it’s a technique by which 3D artists define simulated visual details of different types of materials (of real life or fictional) and apply those details to polygon meshes and other types of 3D model surfaces.
• Basically, any plain 3D model created by any 3D modeling tool, is a mere collection of polygon meshes or curved surfaces (NURBS). Upon creation, a 3D model does not have any visual qualities besides its geometrical outline. One may say, that except
  some basic & limited default material attributes generated automatically by the 3D software applies to all newly models, they still lacks surface qualities like, texture, noise and dirt, reflectance, specularity, glossiness and many other material qualities and behavior of light.
  
• 3D models like creatures, architectural structures, nature objects, machines, vehicles etc. are often designed to create an illusion of imagery or actual reality. This is mostly achieved by assigning Materials to the models. In 3D modeling software, 'Material' is a data object with a collection of user editable settings, where the above mentioned surface qualities can be defined, controlled, and adapted to requirements.
• There, the user also sets the numerical values to determine the ways light would interact with the surface (glossiness / reflections / refractions / transparency etc.). The user also defines there, the image maps as inputs for material parameters, using a special kind of a gray-scale texture map images called “alpha” whereby black and white colors are translated into numerical values. Some texture elements may be defined by additional methods;