(CNN) – The European Union (EU) is possibly the most powerful block in the world. But he is about to lose the United Kingdom, one of its largest members. How and when the United Kingdom leaves the EU will have implications that will spread across the planet.

So, have you heard of brexit but have not been up to date with every turn of events? Don't worry, here's everything you need to know to become an expert.

What is brexit?

Great Britain + departure (exit) = brexit. It is the idea (once unthinkable) that the British leave the European Union. But in a surprising result, the United Kingdom voted to do just that in a referendum in June 2016.

READ: 5 keys to the brexit agreement for the United Kingdom's departure from the European Union

Since then, there have been conversations, disputes, accusations and threats, as in a typical divorce.

But the United Kingdom and the EU could finally have reached an agreement where they can finalize their division.

The process of leaving the United Kingdom from the European Union will last about two years.

How does brexit impact the rest of the world?

If you are a European nation: You have a lot to lose, on many fronts. Just under half of UK exports go to the EU. Just over half of its imports come from the other 27 nations of the block. All of that is now part of a (painful) renegotiation. Now think about diplomacy: when Europe did something useful on that front, the United Kingdom, a serious military power, has often been in the driver's seat. Therefore, the EU is losing a heavyweight.

If you are the United States: The world is already dangerous and volatile enough. Some in the United States may worry that the collapse of the union, a vital ally, will unleash more instability. The United Kingdom is also the seventh largest trading partner in the United States.

If you are any other nation: The United Kingdom is the fifth largest national economy in the world. Think about the effect brexit will have on world markets. Even if they don't collapse, the uncertainty is serious enough. Markets, you see, love stability. And unstable markets = potential bad news for your country's economy.

What is the difference between England, Great Britain and the United Kingdom?

Sometimes we use them interchangeably (and incorrectly). So, here is a quick geography lesson.

The United Kingdom is not a single country but a country of countries. It consists of four nations:

  • England
  • Scotland
  • Welsh
  • North Ireland

Britain is the island that has England, Scotland and Wales.

And England is the biggest. It is the most populated part of the United Kingdom and has its capital, London.

And what is the European Union?

The European Union is a block of 28 countries that decided it would be great if their citizens could go on vacation and trade with each other without worrying about the entire bureaucracy.

Its roots date back to the period after World War II. After six years of fighting, Europe was decimated. The economies were in a coma. The old enemies had to accept the fact that they needed to live together (like France and its former occupant, Germany). Thus, little by little, countries began to form alliances.

By the 1990s we had the modern European Union. It represents 500 million people.

The idea is: if you are financially linked, you are less likely to fight and fight.

Sounds like a great idea. So what is the problem with the EU?

Sounds like a happy marriage. But you know how that is. When world events enter, these countries react differently. They fight over how to deal with refugees who arrive at their shores. They cannot agree on financial matters. They are angry because some of them have to come together more than others to rescue countries that are terribly managed. And this has resulted in anti-EU parties throughout Europe.

Has an EU country ever left?

No country has done it, but it is the largest island in the world. Greenland, which is part of Denmark, was part of the EU until it left in 1985. (The rest of Denmark stayed).

The United Kingdom will be the first country in good faith to leave. However, Greece has seriously thought about it. That would be Grexit (a different story).

But think of the precedent that is to be set. When the United Kingdom leaves, other EU countries could also start looking at the exit door. That means the EU could slowly crumble. And that could have huge consequences for the economy and stability. (Do you remember when we talk about why the EU came about?).

What is happening now? Why does brexit return to the news?

They have been trying to forge a divorce agreement, as the United Kingdom will soon be outside the EU trade bloc. The idea of ​​the United Kingdom leaving the EU without a future trade agreement scares British and European businessmen. The negotiations have been tough. So now, after more than two years of discussions, they have come to this: a draft agreement (of 585 pages) that establishes how the United Kingdom will leave the EU on Friday, March 29, 2019.

However, the United Kingdom will remain within the single EU market and will continue to be subject to EU laws and regulations until the end of 2020. That will give everyone enough time to finalize a future trade agreement. Yes, probably two more years of the same.

Therefore, essentially the United Kingdom will remain in the EU for another two years.

And another important thing: the agreement guarantees the protection of more than three million EU citizens in the United Kingdom and more than one million citizens of the United Kingdom in EU countries to continue living, working or studying as they do currently.

What is one of the biggest friction points?

The "hard" border of Ireland. At this time, the border between the Republic of Ireland and Northern Ireland is open. People (and commerce) move between the two nations with ease. There are fears that could change in a Brexit divorce. The Republic of Ireland is in the EU. But Northern Ireland, which is part of the United Kingdom, will not be in the EU trade block after the division.

Normally, that would require a “hard border,” with control points, border crossings and other infrastructure. This could seriously slow down trade and other economic activities.

Will there be a new vote on the referendum?

Some important Britons like former Prime Minister Tony Blair have been asking for this, but no, there is no plan about it. British Prime Minister Theresa May slammed the door on that idea and said a new vote would be a "serious betrayal" of democracy. This draft agreement will be voted by the parliaments of the United Kingdom and the EU. That's it.