Okay kiddo, so you know how sometimes grown-ups pay more money to ride the bus or subway than kids do? Well, not all grown-ups can afford to pay the higher price, so some cities have something called a "reduced fare program."
Basically, this program helps people who have less money pay for their transportation. They apply to the program and if they meet certain requirements (like being a senior citizen or having a disability), they can get a special card or pass that lets them ride the bus or subway for less money.
By having this program, it helps make sure that everyone can still get to work, school or appointments even if they don't have a lot of money. It's just one way that cities can try to help everyone get around and be part of the community.