Short answers, pulled from the story.
The German Confederation was an association of 39 predominantly German-speaking sovereign states in Central Europe. It was created by the Congress of Vienna in 1815 to replace the Holy Roman Empire, which had dissolved in 1806 during the Napoleonic Wars.
The German Confederation was established by the 9th Act of the Congress of Vienna on the 8th of June 1815. It dissolved after the Austro-Prussian War of 1866, with Austria accepting its end in the Prague peace treaty on the 23rd of August 1866.
Most historians consider the German Confederation weak and ineffective because its most important decisions required unanimity, giving even the smallest states a veto, and its purpose was limited to security matters. Its functioning also depended on cooperation between Austria and Prussia, who were often in opposition.
The German Confederation had only one organ, the Bundesversammlung or Federal Convention, which met in Frankfurt and consisted of appointed plenipotentiaries from the member states. There was no head of state, though the representative of Austria permanently presided as the presiding power.
Austria and Prussia were the two most populous and powerful members of the German Confederation, and the union depended on their cooperation. Their rivalry grew, especially after 1859, and ended with Prussia's victory in the Austro-Prussian War of 1866, which dissolved the Confederation.
The German Confederation was succeeded by the Prussian-dominated North German Confederation, created in 1867 as a true federal state. After the Franco-Prussian War, the southern German states joined, and the German Empire was proclaimed at Versailles on the 1st of January 1871.