Eu is a term that can refer to the European Union, a political and economic union of 27 European countries. Established to promote peace, stability, and economic cooperation, the EU allows for free movement of goods, services, people, and capital among member states. It has its own institutions, such as the European Parliament and the European Commission, which help govern and implement policies. Another meaning of Eu is the prefix used in scientific terms, particularly in biology, to denote something that is true or good. For example, in taxonomy, Eukaryotes are organisms whose cells have a nucleus, distinguishing them from Prokaryotes, which lack a defined nucleus.