This review paper covers one of the most important discoveries of the last century, viz. X-ray diffraction. It has made enormous contribution to chemistry, physics, engineering, materials science, crystallography and above all medical sciences. The review covers the history of X-rays detection and production, its uses/ applications. The scientific and medical community will forever be indebted to Röntgen for this invaluable discovery and to those who perfected its application.

Iqra Zubair Awan