The Federal System is applied to the country where 2 systems of administration prevail at a time; the Federal Government and the Provincial Government. Pakistan is such a country where both the types of governments prevail. The Federal constitution decides about the rights, power & duties of the Center & Provinces.
If any dispute, regarding any matter, is created between the center & the province/provinces, the verdict is given by the superior court (Supreme Court) of country.
Under federal system, provinces enjoy autonomy but they remain under center as an integrated nation. Every province has right to frame laws for itself through provincial assembly. The Federal Government is authorized to tackle affairs on country level while provincial government deals with affairs only which have concern with provincial concerned.