The super keyword in Java is used to access members of the parent class from a subclass. For instance, in a Cat class that extends an Animal class, super allows access to Animal's methods or constructors. One key use is calling overridden methods from the superclass. In the example, the Cat class overrides the makeNoise method from Animal. To execute the original Animal version within Cat's method, use super.makeNoise(). This ensures subclasses can leverage parent class functionality while adding their own behavior.