X-Ray Diffraction (XRD) is one of the most powerful techniques to study the crystal structure of a material. However, there is a long way to travel to get the exact crystal structure of your own material from your XRD data. A preliminary analysis of XRD data can only confirm the phase formation and crystallite size of the material. But, if you are a professional researcher, it is not enough to complete your studies. A qualitative and quantitative analysis on the changes in a crystal system induced by impurities/doping/substitution can be done by Rietveld refinement of the XRD data. Rietveld refinement of a good quality XRD data can give important information of material including crystal structure, Unit cell parameters, atomic position, bond angle and bong length between each atom etc.. which can improve the quality of research. The following article (J. Appl. Cryst. (1999). 32, 36-50) will be helpful for those who want to know more about Rietveld refinement.