Let’s talk fares. In simple terms, fare is a fee paid by an individual to travel on an aircraft. Airfares are totally different than fares on your local transit system, where you pay the same rate to travel from point A to point B as everyone else on the train/bus with you, senior, children, student, etc discounts aside.
The Y fare refers to the highest economy fare sold on a route. It is usually an unrestricted fare, changeable without penalty and fully refundable. Some carriers do not sell any refundable fares. Jetblue is an example of a carrier that does not sell any refundable tickets.
Open tickets are usually sold at the Y rate because of this lack of restriction. An open ticket is one that can be used on any flight in which seats are still available(and often if they aren’t because a person who paid that much for a ticket is the LAST person an airline wants to bump off a plane). Not every airline sells open tickets either.
The lower fares generally much more restrictive. Just remember, for most carriers, the more you pay, the less restrictions you get. Every carrier is a bit different however.
The Y class fare is most popular among businessmen, who may change their plans dozens of times and need to cancel, change, or otherwise alter their trip due to the demanding nature of their job.