Ethnic hatred is when people don't like other people just because they are from a different group or ethnicity. This means they might be different in the way they look, speak, or behave, and because of that, some people may start to act poorly towards them.
Some people might say mean things, exclude them from things or even be violent towards them. This behavior is not nice or fair, and it is important to remember that people should be treated kindly and with respect no matter where they come from or what they look like.
It's just like when you meet a new friend: it's great to learn about their differences and find common things to share. It makes the world a much more interesting and fun place to be.