The Delta Quadrant is one of the four main regions of the Milky Way galaxy, located opposite the Alpha Quadrant, where Earth is situated. It is known for its diverse range of star systems, planets, and species, many of which are explored in the science fiction series Star Trek: Voyager. In the series, the USS Voyager becomes stranded in the Delta Quadrant, leading to encounters with various alien civilizations, including the Borg and the Neelix. The Delta Quadrant serves as a backdrop for themes of exploration, survival, and the complexities of interstellar diplomacy.