The European Union is a group of 27 countries throughout Europe that have combined to form a union that is based on political and economical compatibility and fusion.

Abbreviations are used to represent a number of different organizations and branches within the Union. Because the European Union is a very expansive grouping of different countries, it can be expected that there are a number of different terms for the many groups, organizations and branches within the European Union.
Just as with any other governmental union, there are different branches of the government that include their own organizations and offices. In order to communicate what these organizations and offices are in a brief manner, abbreviations are used. For example, if you wanted to mention the European Broadcasting Union it would be much simpler to address this entity as the EBU-UER. Likewise, if you wanted to mention the European Free Trade Association, you would address this organization as the EFTA.
In general, it is simply much easier to address many of the organizations, programs and offices of the European Union by the established abbreviations. For the most part, the abbreviations are very well known, making it easy for everyone to know which organization, office or program that is being referred to without much of an issue.