There's a change coming up in Europe that will dictate the next five years of policymaking in the region. Four of the highest-ranking jobs at the EU will be vacant before the end of the year, and the race to fill them has already begun. Europe will have a new president of its Parliament (its legislative arm), of its European Council (the heads of state), of the European Central Bank and of the Commission (the executive arm). Arguably, the attention is now more on the latter, given that she or he will determine which direction Europe will take.

What's the European Commission?

It proposes new laws and is generally seen as the government of the European Union. It is formed by one commissioner from every member state plus its president. The different policy areas, from finance, migration and foreign policy, are divided across the 28 officials.

European Union (EU) flags fly from flag poles outside the Berlaymont building. Bloomberg | Bloomberg | Getty Images

How is the president chosen?

The European Union is still battling over how this actually happens. There is one process available called Spitzenkandidaten — which chooses the next president of the Commission based on the number of votes that each European political party receives. This means that the political family with the highest number of seats at the European Parliament nominates one of their members to take the role. This happened at the last election in 2014, which saw the largest political party in the European Parliament — the conservative EPP (European People's Party) — appointing Jean-Claude Juncker as European Commission president. However, some countries believe this process is a "democratic anomaly." The heads of state want to have the final say on who gets the most senior job in Brussels. "The idea that the Spitzenkandidaten process is somehow more democratic is wrong," Donald Tusk, president of the European Council, said last year.

Who are the candidates?

Despite the row over the selection process, some European parties have put forward their leading candidates.

EPP – the conservative right-wing party, has chosen Manfred Weber. He's a German national and has been a lawmaker in Brussels for 10 years. Speaking on the section process back in April, he told CNBC: "It's not a competition between institutions. People outside of Brussels don't care about this institution perspective." He added that he has the support of nine EU member states, which he described as a "good start." The pick for next president of the European Commission will be made by a formal decision by the EU heads of state. This means that the U.K. will also have a say, if it wants, in this process. Otherwise, given that the country is scheduled to leave the European Union this year, Prime Minister Theresa May may decide to abstain. Either way, the next Commission president will be chosen by a reinforced qualified majority — which means they have to gain a certain amounts of votes from leaders who account for a specified amount of the region's population of 500 million.

S&D (Progressive Alliance of Socialists and Democrats) — the socialist party has nominated Frans Timmermans, a Dutch man, currently serving as a vice-president of the European Commission. In his job, he has challenged Poland, Hungary and Romania on their attitude toward the rule of law. ECR – the Alliance of European Conservatives and Reformists has selected Jan Zahradil, a Czech lawmaker in the European Parliament. EFA – the European Free Alliance, which brings together various regional political parties, from Scotland to Spain, nominated Oriol Junqueras, who is currently in prison. He was a member of the Catalonian Parliament and supportive of the region's independence from the rest of Spain. He told CNBC via email that he put himself forward despite being in prison to "to denounce and fight repression by Spain." Other parties have decided to put forward more than one candidate, giving more leeway to European leaders when voting on the next president. ALDE (Alliance of Liberals and Democrats for Europe group) – the Liberal party at the European Parliament nominated seven candidates, dubbing them "Team Europe." In this group, there's the influential Margrethe Vestager, the Danish official currently serving as EU competition commissioner.

She told CNBC that the next European Commission should focus on climate change, cybersecurity and providing a good future for the younger generations. Meanwhile, The Green Party decided to nominate two people: the German lawmaker Ska Keller and the Dutch politician Bas Eickhout. The European Left Party also elected two members as potential leaders of the Commission: Violeta Tomic from Slovenia, and Nico Cue, a former Belgian trade union leader.

Any non-official candidates?

Michel Barnier during a news conference after a meeting of EU finance ministers at the European Council headquarters in Brussels, Belgium. Jasper Juinen | Bloomberg | Getty Images