Constitutional law is a body of law which defines the role, powers, and structure of different entities within a state, namely, the executive, the parliament or legislature, and the judiciary; as well as the basic rights of citizens
Fundamental rights are a group of rights that have been recognized by the Supreme Court as requiring a high degree of protection from government encroachment. These rights are specifically identified in the Constitution, or have been found under Due Process. Laws encroaching on a fundamental right generally must pass strict scrutiny to be upheld as constitutional.
Public interest litigation is the use of the law to advance human rights and equality, or raise issues of broad public concern. It helps advance the cause of minority or disadvantaged groups or individuals. Public interest cases may arise from both public and private law matters.
A writ petition is essentially a court petition for extraordinary review, asking a court to intervene in a lower court’s decision. A writ means an order. A warrant is also a type of writ. Anything that is issued under an authority is a writ.
The Supreme Court of India is the highest judicial forum and final court of appeal under the Constitution of India, the highest constitutional court, with the power of constitutional review.