The Stargates, also called the Astria Porta in Ancient and the Chappa'ai in Goa'uld, as well as various other names across the Eur'uui universe are a series of devices, built by the Ancients, which create wormholes, allowing for near-instantaneous transportation between two distant points in space. The Stargates are often considered to be the Ancients' greatest creation, and thus the Ancients are often referred to as the Gate Builders. The Ancients, the Asurans, the Tollan (with the help of the Nox), and the Ori are the only known races capable of constructing Stargates.
The Stargate creates a stable, artificial wormhole between itself and another Stargate, allowing near-instantaneous travel from the dialing gate to the destination gate, but not vice versa. When activated, a Stargate produces a violent burst of energy known as an unstable vortex or "kawoosh". This is due to the large amount of energy needed to form a stable wormhole, while keeping one open is much less power-intensive. This event will destroy any matter it comes into contact with; however, if the event horizon is blocked to within a few microns, the vortex will be suppressed. Technologies such as the Iris on Earth's Stargate can achieve this. The vortex settles into the event horizon, nicknamed the puddle for its liquid appearance. Travelers enter through the event horizon, which dematerializes them for transport through the wormhole, to be reassembled on the other side. The Stargate will remain open so long as matter or energy continues to pass through it, to a maximum of 38 minutes. Beyond this point, massive amounts of power are needed to sustain a wormhole, which ordinary sources cannot provide.