The Federation's fleet of exploratory, scientific and defence vessels, founded in the 22nd century.
Starfleet is the exploratory and defence arm of the United Federation of Planets, responsible for the discovery of new worlds and the protection of the Federation. It operates a fleet of starships and many bases, and its members are drawn from the many species of the Federation.
The organisation is guided by principles such as the Prime Directive, which forbids interference in the natural development of other cultures. Its officers are trained to deal with the unexpected and to make decisions on their own initiative. Starfleet's roots go back to the twenty-second century and the early days of human space exploration.
Every Star Trek series follows the work of Starfleet, from Captain Kirk and the Enterprise to Captain Picard's era, and Captain Sisko's work on Deep Space Nine. Starfleet is shown as a force for good in most stories, although several episodes explore its failings. The ideals which it represents are at the heart of the franchise.