Step 4. European elections
Elections to the European Parliament are held every 5 years. The rules governing the European elections differ from Member State to Member State, however they have to comply with some form of proportional representation. A specific number of mandates is allocated to each Member State. This number depends on the size of the population of each country, with smaller countries receiving more seats than strict proportionality would imply (so-called degressive proportionality). Interestingly, the European elections are contested and campaigned by national political parties, which select candidates and organise election campaigns. However, once MEPs are elected, most of them opt to join one of the political groups in the European Parliament.
Now watch this video explaining the functioning of Political Groups in the European Parliament.