Okay kiddo, so let's start with some big words. Antifascist means people who are against the idea of fascism. Fascism is when a group of people believe that they are better than others and they can treat them badly just because they are different. Slavs are a group of people from a specific part of Europe. Hungary is a country in Europe where some Slavs live.
Now, the Antifascist Front of Slavs in Hungary is a group of people who are Slavs and they don't like the idea of fascism. They want to make sure that everyone is treated fairly and equally, no matter where they are from or what they believe in.
It's important to have groups like this because sometimes people can be mean to others just because they are different. This group is saying that it's not okay to be mean to someone just because they are a Slav or because they have a different opinion.
So basically, this group wants everyone to be nice to each other and not discriminate against anyone because of where they come from or what they believe in.