The European Union is an economic and political union between (after Brexit in 2020) 27 European countries. It was created after World War II as the European Coal and Steel Community in 1951 with six member states, evolving into the European Economic Community in 1958. Its focus is the single market, enabling goods, services, capital, and people to move freely within the EU. It is a supranational, or regional, organization, based on a partial surrender of sovereignty among its member states.
The European Union is based on treaties, approved by all member states. Its founding treaty is the Treaty of Rome, with amendments including the Treaty of Maastricht and the Treaty of Lisbon. Human rights within the European Union are protected by the EU Charter of Fundamental Rights.
There are four major institutions related to European Union Law: the European Commission, the Council of the European Union, the European Parliament, and the Court of Justice. These institutions and the other EU institutions are identified and linked on:
European Union Law, Including Brexit and Beyond, in a Nutshell by 
Principles of the European Union Beyond Brexit by 
Research Handbook on EU Institutional Law by 
Research Handbook on the European Union and International Organizations by 
