Okay kiddo, so you know how some people are boys and some people are girls, right? But some people don't feel like they fit into either of those categories. They might feel more like they're in the middle, or not really either one.
These people are called non-binary, and it means that they don't identify as male or female. And some places have decided that they want to recognize non-binary people as a real and valid gender. This means that people can put something other than "male" or "female" on their official documents like their birth certificate or driver's license to show that they are non-binary.
It's important for people to be able to express who they really are, and this helps make sure that non-binary people are treated with respect and equality. It might take some time for everyone to understand, but it's an important step towards making sure everyone is recognized and valued for who they are.