Explain the following: Writ of Mandamus.

Writ of Mandamus: The expression "mandamus" means a command to act. The writ of mandamus is, thus, a command issued to direct any person, corporation, inferior Court or Government authority requiring him to do a particular thing therein specified which pertains to his or their office and is further in the nature of a public duty. This writ is used when the inferior tribunal has declined to exercise jurisdiction or to a government authority not exercising the delegated power. Mandamus can be issued against any public authority. The applicant must have a legal right to the performance of a legal duty by the person against whom the writ is prayed. Mandamus is not issued if the public authority has a discretion. Mandamus can be issued by the Supreme Court and all the High Courts to all authorities. However, it does not lie against the President of India or the Governor of a State for the exercise of their duties and powers (Article 360). It also does not lie against a private individual or body except where the State is in collusion with such private party in the matter of contravention of any provision of the Constitution or of a Statute. It is a discretionary remedy and the Court may refuse if alternative remedy exists except in case of infringement of Fundamental Rights.