The American National Standards Institute (ANSI) is like a teacher who makes sure everyone is following the same rules. Just like how your teacher makes sure everyone follows the same rules in the classroom, ANSI makes sure everyone follows the same rules when it comes to making products and doing important tasks.
For example, think about how you need to follow certain rules when you're playing a game with other kids. You might have rules like "no hitting" or "take turns." ANSI does the same thing, but for grown-up things. They create rules (called standards) for things like making sure buildings are safe, making sure the food you eat is safe, or making sure the wires in your house don't cause a fire.
ANSI gets lots of people together (like teachers get lots of kids together in a classroom) and they all talk about what the rules should be. Then, they make a list of all the rules and everyone agrees to follow them. Then, companies and organizations follow these rules so that they are safe and high quality for everyone to use.
So, just like your teacher helps everyone follow the same rules in the classroom, ANSI helps everyone follow the same rules in the bigger world so that everything is done safely and properly.