Imagine you and your friends are playing a game and you make a rule that you are the leader and you make all the decisions. Everyone agrees to this rule and you all keep playing.
Now, the Autonomous Republic of Crimea is kind of like that game. It is a region of land that is a part of a bigger country called Ukraine, but it also has its own rule book called the constitution. In this rule book, it says that Crimea gets to make some of its own decisions, like who becomes the leader and what laws they follow.
In 2014, some people in Crimea didn't like the leader that Ukraine had chosen, so they decided to make their own rule and have their own leader. They had a big vote where people could say they wanted to be a part of Ukraine or they wanted to be independent. The majority of people voted to be independent and to have their own leader.
However, Ukraine and many other countries didn't agree with this decision. They said that Crimea was still a part of Ukraine and that they couldn't just go off and do their own thing. This disagreement led to a lot of tension and even violence in the region.
So, in summary, the Autonomous Republic of Crimea is like a game where the region has its own rule book and gets to make some of its own decisions, even though it is still a part of a bigger country called Ukraine. In 2014, some people in Crimea decided to break away and have their own leader, which caused a lot of problems.