Esperanto is a made-up language some people created a long time ago that was supposed to be easy for everyone to learn. It's like a secret code that people can use to talk to each other in a way that not everyone else understands.
The cool thing about Esperanto is that there are no irregular verbs or complicated grammar rules like there are in other languages. It's kind of like if the words were all puzzle pieces and you can just fit them together no matter what order you put them in.
Esperanto doesn't come from any particular country or culture, which makes it a very neutral language. That means it doesn't belong to any one group of people like English belongs to people in England or Spanish belongs to people in Spain. It belongs to everyone who speaks it.
People use Esperanto to talk to each other about all sorts of things, like what they did that day or what they like to eat. It's like having your own secret club where you can talk to people from all over the world.