It gives legal right to protect authors of documentation or software from unauthorized copying or selling of their work. 
The 1886 Berne Convention first Internationally established recognition of copyrights.
Copyright law of India The Copyright Act 1957 was the first post-independence copyright legislation in India. 
The most recent amendment was in the year 2012, through the Copyright (Amendment) Act 2012. 
Duration of Copyright In the case of original literary, dramatic, musical and artistic works, 60 years counted from the year the death of the author.




The copyleft symbol is a backwards "C" in a circle
Copyleft  concept pioneered by Richard Stallman. 
A Copyleft is the opposite of a Copyright.
Copyleft laws have provided users the same rights as copyright authors,in simple words they can also copy, modify and distribute the materials. Means copyleft type licens s are made to ensure a creative work remains freely available. e.g.  Mozilla Public License