I often sell Charter Flights to my customers. They tend to immediately think, "A small puddle Jumper." This is the farthest from the truth and I would like to set the facts straight.
Usually, a charter flight is a large airline who works with a 3rd party company to guarantee the selling of all flights in order to offer a discount rate to their customers. Typically, they fly to a destination on one day and will return on another. Sometimes, there are 3,4,5 and 6 day charter flights to the Caribbean. You cannot purchase these flights on your own, only travel agents can offer these to their clients at the discounted rate.
Usually these Charter companies market comfort, including legroom that is at least comparable to what first-class passengers would experience on a typical commercial domestic flight. Some carriers have greeters at their lounges. Food, beverages, cocktails and WiFi are typically offered at no extra charge. And tickets can be changed during the process.