John Stuart Mill’s Ethical Theory

Explain John Stuart Mill’s Ethical Theory, commonly called “Utilitarianism” (sometimes summed up as choosing “the greatest good for the greatest number of people”). How does he expand on Jeremy Bentham’s views. How is this fundamentally different from Kant’s “Deontological Ethics?” Given this view of “Utilitarianism,” which seems to suggest that the end justifies the means, and further, that human beings are NOT ends in themselves, what would he say about those who are “differently-abled?” (either emotionally, mentally, or physically handicapped) in the following video: https://youtu.be/s9BUT6IrZ3g?