Okay, so you know how sometimes people have different opinions on things? Well, sometimes people can have really strong opinions that make them want to do extreme things that are not always good for everyone. That's what the "far-right" is all about.
In Spain, the far-right has been around for a long time, but it became more popular in the 1930s and 40s. During that time, Spain had a dictator named Francisco Franco who was part of the far-right. He believed that only certain people should have power and that other people who were different from him were not as important.
After Franco died in 1975, Spain became a democracy and many different political parties formed. Some of these parties are part of the far-right and they still believe in similar things to Franco. They think that only certain people should be in charge and they don't want to have equal rights for everyone.
The far-right in Spain has been responsible for some violent acts, like attacking people who are different from them or protesting against things they don't believe in. This is not okay and it's important for everyone to remember to be kind and respectful to each other, even if they don't always agree.