The field of films and coatings is very broad. In general, the structure of films may comprise several phases, each having a different micro-structure and composition. These phases may be built up from grains which have different sizes, shape, morphology and orientation. A description of those types of films is complex and a large number of structural parameters is needed to fully characterize them. It is therefore more convenient to use a statistical description of them and to specify the relative proportion of different phases, grain orientation distribution , the orientation correlation between neighbouring crystals  and grain shape and size distribution . Such a description provides details of the microstructural geometry of films, thereby giving a frame of reference within which various properties of films and a microstructural transformation of film structure, can be analyzed. Such microstructural descriptions have to be often supplemented by information about the nature and distribution of lattice defects, dislocations, stacking faults and antiphase boundaries. All this information put together, helps to provide a better understanding of the behaviour and various physical, chemical, mechanical and other properties, of films and coatings.