An international organization is like a special club where different countries come together and decide to work on things that affect all of them. It's like when you and your friends meet up to play together, but instead, different countries from all over the world join together to help solve problems.
These organizations have special rules and people who work for them, just like your club. Some of these organizations are for fun, like the Olympics or the World Cup, while others are for more serious things like protecting human rights, helping people who are affected by natural disasters, or promoting trade between countries.
To join one of these organizations, countries need to agree to follow the same rules as everyone else in the club. They also have to pay money to help fund the organization's work. Just like your allowance, countries have to give a certain amount of money each year to be part of the club.
When all these countries come together, they can do a lot of good things. They can help make sure that everyone in the club plays fairly, and they can work together to create new ideas and solve problems. It's like when you and your friends work on a project together at school, except it's on a much bigger scale with countries from all over the world.