Economic integration is when different countries work together to make their economies work better with each other. It's like when you and your friends join forces to build a really big Lego tower.
When countries integrate economically, they make it easier for people, goods, and money to move between their countries. This can help them save money by trading things they are good at making for things they are not so good at making. It's like when you trade your favorite toy with your friend's favorite toy because you both want to play with something different.
There are different levels of economic integration. At the lowest level, countries just agree to trade with each other. This is called a free trade agreement. It means that they won't put taxes on goods that are coming from the other country.
At the highest level, countries form a single market. This means that they have a common set of laws about trade, and all goods, money, and people can move around freely between the countries. It's like all your friends building a really big Lego city together, and everyone is allowed to move their Lego cars and Lego people around as they please.
Economic integration is important because it can help countries work better together and make everyone richer. By trading with each other and working together, countries can make more things at a lower cost and everyone can benefit.