Okay kiddo, so Lidia Zamenhof was a very important person in the world of language. She was born over a 100 years ago in Poland to parents who spoke different languages, which meant she grew up speaking more than one language too.
Now, back then people in different countries had a hard time understanding each other because they spoke different languages. It was like they were all talking in different codes and couldn't figure out what the others were saying. This made it very difficult for them to work together, trade with each other, and even make friends.
So, when Lidia grew up she became very interested in languages and wanted to find a way to bring people from different countries together. She realized that the way to do that was to make a language that everyone could understand, regardless of where they came from.
So she worked hard and created a new language called Esperanto. And the cool thing about it was that it was made up of lots of different words and grammar rules from lots of different languages, so people from different countries could all understand it. Esperanto was like a secret code that everyone could speak and decode.
Lidia Zamenhof was one of the main people who helped spread Esperanto all over the world. She taught it to people and wrote books in it, so more and more people could use it to communicate with each other.
Thanks to Lidia and others like her, people in different countries now have a way to understand each other and work together. So you could say, she helped make the world a more friendly and connected place.