One-day track and field meetings form the most common and seasonal aspect of the sport – they are the most basic level of track and field competition. Meetings are generally organised annually either under the patronage of an educational institution or sports club, or by a group or business that serves as the meeting promoter. In the case of the former, athletes are selected to represent their club or institution. In the case of privately run or independent meetings, athletes participate on an invitation-only basis.