What is the meaning and basis of judicial review?

In many countries with written constitutions, there prevails the doctrine of judicial review. It means that the constitution is the supreme law of the land and any law inconsistent therewith is void. The courts perform the role of expounding the provisions of the constitution and exercise power of declaring any law or administrative action which may be inconsistent with the constitution as unconstitutional and hence void. This judicial function stems from a feeling that a system based on a written constitution can hardly be effective in practice without an authoritative, independent and impartial arbiter of constitutional issues and also that it is necessary to restrain governmental organs from exercising powers which may not be sanctioned by the constitution.