The Congress of Vienna in 1815 was convened by European powers to establish a balance of power amongst them after Napoleon’s defeat. The aim of the congress was to ensure that no other dictatorship as that of Napoleon is ever established in Europe and further to maintain peaceful existence amongst the different nations. The other aim for the congress was to prevent uprisings that sought to topple established structures of governance and authority and aimed at maintaining the status quo among the different countries in Europe.
Although the Great Powers fought together to oust Napoleon there were preexisting issues among them chiefly between Russia and Prussia and between Britain and Austria. Apart from boundary issues among the European nations, other issues discussed included abolition of slavery and rights of German Jews.
Regarding the maintenance of the status quo and preventing future political uprisings the issue was addressed as exemplified by discussions about the of restoration of the Bourbon royal family in France.
The Congress of Vienna was convened in 1814. Its major purpose was to set up an international order for Europe after the Napoleonic Wars. In other words, the Congress met to decide things like which lands would be controlled by who and to set up the "rules" by which European affairs would run.
As an example of the first type of thing, the Congress set up the Netherlands as a new country and they created the states of Genoa and Piedmont in Southern Europe. They also set new boundaries for various countries like Prussia.
As an example of the second, they restored to the throne various dynasties that had been overthrown by Napoleon. In doing so, they were essentially saying that Europe would go back to being a region of monarchies.
Overall, the point of the Congress was to try to set up a system whereby Europe could be at peace. The Congress tried to do this by setting new boundaries and by doing things like reestablishing the monarchies in hopes that that would prevent further wars within countries.