The official site of the European Union is called "europa.eu" instead of "europe.eu" because the word "Europa" has a specific meaning in the context of the European Union. In Greek mythology, Europa was a Phoenician princess who was abducted by Zeus, the king of the gods, in the form of a white bull. Europa's name is often used as a symbol of Europe, and the official site of the European Union uses the name "europa.eu" to reflect this symbolism.

The word "europe" is simply the English word for the continent of Europe. While the two words sound similar, they have different meanings. The word "europa" is specifically associated with the European Union, while the word "europe" is more general and can refer to the continent as a whole.

Using the name "europa.eu" for the official site of the European Union helps to emphasize the organization's connection to the continent of Europe. It also helps to distinguish the site from other websites that are about Europe, but are not affiliated with the European Union.

In addition to the symbolic reasons for using the name "europa.eu", there are also practical reasons. The domain name "europa.eu" was available when the European Union was first setting up its website, while the domain name "europe.eu" was already taken. This made it easier for the European Union to acquire the domain name "europa.eu" and to launch its website.

Today, the domain name "europa.eu" is one of the most popular websites in the world. It is used by millions of people every day to access information about the European Union and to participate in its activities. The use of the name "europa.eu" helps to ensure that the website is easily accessible and that it is associated with the European Union.