What is the difference between domestic and foreign policy ?

"Domestic policy are administrative decisions that are directly related to all issues and activity within a nation's borders. It differs from foreign policy, which refers to the ways a government advances its interests in world politics"

Difference Between Domestic & Foreign Policy. ... Domestic policies are those that affect or apply to people or institutions within a particular country and tend to be internal. Foreign policy has to do with policies between two or more nations and is external. It focuses on building networks with other countries

Cases were centered around a water pump.

Explanation:

Dr. John Snow was an English physician, considered one of the fathers of modern epidemiology. He is particularly well-known for having traced the source of a cholera outbreak in Soho, London, in 1854. Snow noticed that houses which were infected with cholera all surrounded a water pump. he concluded that the cholera virus must be transmitted through the water. His findings led to fundamental changes in the water and waste systems in London, and these were later adopted by many cities around the world.