After World War II, there were a lot of people who were against the ideas of fascism, which is a bad government system where the leader has all the power and doesn't care about what the people want.
These people who were against fascism, known as anti-fascists, wanted to make sure that their country never became fascist again. They wanted to spread the idea that everyone should be treated equally and have a say in their own government.
So, they did a lot of things to fight against fascist ideas. They taught people about the dangers of fascism and how it can lead to terrible things like war and discrimination. They also tried to expose any fascist groups that were trying to take over the government or spread hate towards certain groups of people.
Overall, the post-World War II anti-fascism movement was all about making sure that people understood that everyone should have a voice in their own government and that we should all work together to make sure that these terrible ideas don't take hold and cause terrible things to happen.