They scapegoat people, they bully people, are racist, or categorize a whole group of people in a very prejudiced way. Hate speech is very dangerous and is different from just cursing someone out and getting angry. Hate speech is racist, prejudiced speech that denigrates a whole group of people, not just an individual. Hate speech demeans the group, proposes violence toward it, or extermination or elimination of that group. Hate can be expressed violently or by means of discrimination, such as suggesting throwing a group of people out of a neighborhood.
Hate speech is a legal term.
It is against the law. Some kids at my school are scary, like you're describing. A. Talk it over with adults whom you trust, both within the school and in your family, not just to express your feelings, but to come up with some way to get control of the situation. You may have reason to be afraid, but you may not. If you're afraid because kids are carrying knives or guns or threatening other people, or you just get a creepy feeling, trust that feeling and try to make adults aware of it.