The wormhole is discovered in the first episode of Star Trek: Deep Space Nine. It is found to lead from the Bajor-B'Hava'el system in the Alpha Quadrant to the Idran system in the Gamma Quadrant, seventy thousand light-years away on the other side of the galaxy. Due to the phenomenon's strategic importance, the station Deep Space Nine is moved from orbit of Bajor to near the mouth of the wormhole.
Commander Benjamin Sisko and Lieutenant Jadzia Dax make first contact with the inhabitants of the wormhole, its creators, extra-temporal and nearly omnipotent energy beings known to the Bajoran religion as the Prophets. It is they who provided the Tears of the Prophets or Orbs (energy artifacts) to the Bajorans; these artifacts' revelations, conveyed through hallucinic experiences, became the basis of the Bajoran religion.
The wormhole becomes a point of conflict throughout the series, since it permits the incursion into the Alpha quadrant of the Dominion, a belligerent union of races led by the shapeshifting Founders.
The wormhole is at one point collapsed by the destruction of one of the Tears of the Prophets at the hands of the Prophets' enemies, the Pah-Wraiths. It is later restored by the discovery of an additional orb.
The wormhole appears as an aperture of swirling golden light surrounded by blue clouds, which appears when a vessel approaches and disappears when the vessel enters it; it also appears when discharging a vessel. The wormhole may only be traversed by ships traveling at impulse (sub-light speed) velocities.
It is described as a verteron tunneling phenomenon, and the orbs are also supposed to be verteron energy fields. (Verterons are a notional sub-atomic particle.)
An attempt to create a similar artificial wormhole by the Trill scientist Lenara Kahn failed.