The European Union traces its origins to the European Coal and Steel Community, which was founded in 1951. Nonetheless, if you visit the European Union's official web site www.europa.eu, the project is actually called Europa - the European Union. So where is Europa coming from? Within all the 27 member countries, it is the most neutral way of writing Europe, when it comes to consolidate all languages into one single language. In most member countries, Europe translates into Europa. Also the name of the continent has its origins from a character in Greek mythology that was called Europa.
The Union is derived from Latin and means federation, consortium or as it is simply used in English: unification or Union.
When the European Union was founded in 1993, the members of the formerly known European Community gave it its name. 
Corresponding to the official EU web site, the European flag consisting of 12 stars in a circle, symbolize the ideals of unity, solidarity and harmony among the people of Europe.
The European Union also has an anthem coming from the Ninth Symphony by Beethoven. The motto of the EU is united in diversity.