Wikipedia is like a big book, but it's not made of paper. It lives on a website on the internet where people can write and read articles about all sorts of things. But, just like a regular book, Wikipedia had to start somewhere.
Around 20 years ago, in 2001, a man named Jimmy Wales and his friend Larry Sanger wanted to create a place on the internet where people could share information and knowledge with one another. They called it "Wikipedia." At first, they only had a few articles that they wrote themselves, but then they opened up the website for anyone to write on.
Over time, lots of people started writing articles for Wikipedia. Some people wrote about history, others wrote about science or animals, and some wrote about video games. Every article gets read and reviewed by other people who want to make sure the information is true and helpful.
Nowadays, Wikipedia has over 6 million articles written by people from all over the world. It's the biggest and most widely-used encyclopedia in the world! So, if you've ever used Wikipedia to find information for a school project or just for fun, you're a part of its history too!