The Scout troop is a collective term for a group of Scouts, Boy Scouts, Girl Guides and Girl Scouts that is composed of Scouts, typically children of both or either sex, ages 10 to 18 years depending on their national association. Girl Guides often use Unit or Company instead. The troop is the fundamental unit of a Scout group, which a Scout joins and via which he or she participates in Scouting activities. The troop size can vary from as few as a half-dozen Scouts to several dozen.