As compared with regulations which are, in principle, binding in their entirety, directives issued by the EU institutions are binding as to the result to be achieved, and the deadline for the result to be achieved, upon each Member State to which they are addressed and the choice of the method is left to the state concerned. Therefore, directives are binding to the time and the purpose, but leaves discretion to the Member States as to the method and instrument. A directive also has a binding effect but only against the Member State to whom it is addressed and only in relation to the result to be achieved. Directives are not automatically applicable within the Member States since Member States exercise discretion to select the appropriate form of domestic law to incorporate the obligations arising from the directive into national law. Directives are not meant to be an instrument of uniformity. They are used for the approximation or harmonisation of national legal systems.