Answer: this congress (presided by Austrian chancellor count of Metternich) intended restoration legal dynasties in their thrones ....that is why Bourbons got back to France, Spain, to the kingdom of Two Sicilies (capital Naples), why Bragancas got back to Portugal etc etc. In other words Congress intended to restore absolute monarchy in Europe.
Explanation: in spite of these goals, French revolution had still a significant impact in all the Europe. It was impossible to surpress this revolutionary factor in Europe .....movement called "constitutionalism" (or liberalism). To supress this movement European monarchs organized regular "congresses" in all the Europe. Such strategy helped (for example) to supress constitutionalism in Spain in 1823. This "congress strategy" lasted till 1830 (July Revolution in France: last Bourbon king Charles X who intended to rule absolutely was dethroned and died in exile).
