Starfleet is the exploration and defense arm of the United Federation of Planets. It was founded in 2161, composed of portions of the Earth Starfleet, the United Earth military (of which the Earth Military Assault Command Operations division was a part), Andorian Imperial Guard, Vulcan and Tellarite forces. Under jurisdiction of United Earth Space Probe Agency until the late 23rd century, Starfleet Command operates under the Federation Council and is bound by Starfleet general orders and Regulations.
Under normal circumstances, the military of any planet that subsequently entered the Federation is assimilated into Starfleet.
Starfleet operates a vast number of planetary facilities, starships and starbases. Its members wear a uniform, rank pins, and a commbadge shaped like the Starfleet insignia.