In addition to having fields, classes can also have their own method definitions.

These look the same as the method definitions you've seen so far, they are just put within a class definition.¹

class Muppet {
    String name;

    void freakOut() {
        IO.println("**ANGRY KERMIT NOISES**")
    }
}

We call these instance methods because you need an instance of the class in order to call the method.