A law is a precept that directs or prohibits something in agreement with justice. These are statutes enacted by the authorities and obey certain principles, such as the generality (they are all individuals) and mandatory (they are mandatory), among others.
Organic law means any law necessary from the constitutional point of view to settle the business of social life. The organic laws have a different skill than ordinary laws, and they require some special requirements, like the absolute majority at the time of their approval.
The French Constitution of 1958 is their origin. Although they depend on each national legislation, the organic laws are considered as a link or an intermediary step between ordinary laws and the Constitution. The particular characteristics of the organic laws require the vast parliamentary majority (because it is fairly delicate themes for society) as well as high stiffness in the regulation (the organic laws are not changed easily or even the will of a Governor).
That said, the organic laws deal with the development of public authorities and of fundamental rights. In France, for example, the organic laws are established by the Constitution of 4 October 1958 (promulgated by René Coty) and complement.
The Constitutional Council must be entered to verify the constitutionality of a law. However, there does not need to be before it when it comes of an organic law. The principle of jurisdiction is the most usual way to establish relationships between organic and ordinary laws.