Galactic quadrant

In the fictional universe of Star Trek, the Milky Way Galaxy is divided into four quadrants, which are further subdivided into sectors. The quadrants are designated by the Greek letters Alpha, Beta, Gamma, and Delta, however their arrangement order is placed neither in a clockwise nor counter-clockwise pattern.

Alpha Quadrant
The Alpha Quadrant would be located between 6 and 9 o'clock positions if the plane of the galaxy were seen as a clock face with the 6 o'clock position bisecting Earth's solar system.

The Alpha Quadrant serves as the usual setting for the television shows Star Trek: The Original Series, Star Trek: The Next Generation, Star Trek: Deep Space Nine and Star Trek: Enterprise as well as most of the Star Trek movies.

The Alpha Quadrant is home to half of the United Federation of Planets, the entire Cardassian Union, the Ferengi Alliance, the Bajorans, the Breen Confederacy, the Tholian Assembly, the Talarian Republic, and the Tzenkethi Coalition. About 600,000 years ago, the Alpha Quadrant was dominated by the Tkon Empire which have long since vanished.

The Bajoran wormhole bridges the 70,000 light-year distance between the Alpha Quadrant's Bajor system and the Gamma Quadrant's Idran system.

Beta Quadrant
The Beta Quadrant would be located between the 3 and 6 o'clock positions if the plane of the galaxy were seen as a clock face with the 6 o'clock position bisecting Earth's solar system.

The reason why the United Federation of Planets and Earth are right on the border between the Alpha and Beta Quadrants is to retroactively offer consistency to references in the original series, its movies, and early episodes of Star Trek: The Next Generation, which use "quadrant" and "sector" interchangeably.

The Beta Quadrant is home to half of the United Federation of Planets, the entire Klingon Empire, the lower part of the Romulan Star Empire, the Gorn Hegemony, the Son'a Solidarity and the Metron Consortium. The Beta Quadrant is also the location of the planet Vulcan.

Gamma Quadrant
The Gamma Quadrant would be located between the 9 and 12 o'clock positions if the plane of the galaxy were seen as a clock face with the 6 o'clock position bisecting Earth's solar system.

The Gamma Quadrant is home to the races of The Dominion, and some of the territory controlled by The Borg Collective.

The Bajoran wormhole bridges the 70,000 light-year distance between the Gamma Quadrant's Idran system and the Alpha Quadrant's Bajor system. This has meant that the United Federation of Planets has not explored much of the Gamma Quadrant.

Delta Quadrant
The Delta Quadrant would be located between the 12 and 3 o'clock positions if the plane of the galaxy were seen as a clock face with the 6 o'clock position bisecting Earth's solar system.

Most of the information about the Delta Quadrant and its inhabitants comes from the show Star Trek: Voyager. Apart from the voyages of the USS Voyager, the United Federation of Planets have not explored this quadrant.

The Delta Quadrant is home to the Borg Collective, the Kazon, the Vidiians, the Talaxians, the Ocampa, and the Hirogen. Species 8472 is first encountered in this quadrant, although they are not native to this region or physical dimension. Most of the Borg Collective resides in the Delta Quadrant although they have Space in the Beta Quadrant as well. A small part of the Romulan Star Empire crosses into this quadrant as well.