Question

Do explain Theory of relativity and special theory of relativity and also state difference between them.

Answer 1

In physics, special relativity (SR, also known as the special theory of relativity or STR) is the generally accepted and experimentally well-confirmed physical theory regarding the relationship between space and time. In Albert Einstein's original pedagogical treatment, it is based on two postulates:

The laws of physics are invariant (i.e. identical) in all inertial systems (non-accelerating frames of reference).The speed of light in a vacuum is the same for all observers, regardless of the motion of the light source.
General relativity generalizes special relativity and Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time, or spacetime. In particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of partial differential equations.