It differs from the more common randonnees or brevets, which are individual events and not specifically competitive.
As with other randonneuring events, flèches are governed by national and local authorities, such as Randonneurs USA (RUSA) which publish the governing rules.
[1] The object of a flèche is to ride the maximum distance in a fixed time, usually 24 hours, and usually finishing at or near a specified location, riding a route that the team has specified before the start; different teams generally do not have to follow the same route.
Flèche competitions traditionally take place on or about the Easter holiday.
In the cycling context it evokes the image of teams converging on a destination as arrows might on a target in an archery competition.