What are the differences and similarities of act utilitarianism and rule utilitarianism?

Policies should be determined by whatever brings the greatest good to the greatest number of people.

They are spelt differently.

'Utilitarianism' means doctrine that the useful is the good; especially as elaborated by Jeremy Bentham and James Mill; the aim was said to be the greatest happiness for the greatest number

Utilitarianism: morality is the result of an act. Focus on the consequences. A moral act is what will bring the greatest amount of happiness for the greatest number of people. Virtue Ethics:...

Utilitarianism promoted policies for greatest goods for numbers of people.