Do you know that some countries are big, and some are small? Montenegro is a small country, and a long time ago, it was a part of a bigger country called Yugoslavia. But in 2006, Montenegro wanted to be its own country, and not a part of Yugoslavia anymore.
So, they had a special vote called a referendum. A referendum is like a big survey where lots of people get to give their opinion about something important. In this case, Montenegrin people were able to vote if they wanted Montenegro to become its own country or if they wanted to stay a part of Yugoslavia.
Lots of people went to vote and in the end, more than half of them chose to make Montenegro its own country. This meant that Montenegro officially became an independent country, with its own rules and government.
It was a very important decision for the people of Montenegro, and it had a big impact on their lives. They were now responsible for making their own choices and building their own future.