What is the difference between PrEP, PEP, and ART?

What is the difference between PrEP, PEP, and ART?

All three contain antiretroviral medicines in different combination for different purposes: PrEP is a pill that has 2 anti-HIV medicines taken daily to prevent HIV for HIV-negative people. PrEP is taken before you think you might be exposed to HIV. PEP is...