Ok, so let's imagine you and your friend are playing a game and your friend does something that is against the rules of the game. You might tell your friend that they have to stop or you won't play with them anymore.
Now, imagine that there are rules that all the countries in the world agreed to follow called laws. Sometimes, people might break these laws in one country but then try to hide in another country where it's harder for the police to catch them.
So, if someone breaks a law in one country and then goes to another country, the first country might want the person to come back so they can be punished for what they did. That's called extradition.
In Nigeria, there are also laws that say if someone breaks the law in another country and goes to Nigeria, they can be sent back to that country to face punishment. This helps make sure that people who break the law can't just run away from their problems.