This term paper focus to Discuss on Special Theory of Relativity. Albert Einstein showed how measurements of time and space are affected by motion between an observer and what is being observed. Theoretical notion of the special relativity has been introduced in Einstein’s book “On the Electrodynamics of Moving Bodies”. Special relativity is dependant on two postulates which are contradictory in classical motion: 1. The laws of physics would be the same in all inertial structures of reference (observers in uniform motion relative to one another) and 2. The speed of lighting in vacuum is same in all inertial frames of guide (all observers, regardless of motion or in the motion of the cause of the light).