Naqahdah

In the fictional universe of Stargate, a number of technologically advanced races and societies have produced a variety of highly advanced weapons, tools, and spacecraft. By liaising with these races and learning from them, Earth too has begun to create its own futuristic technology. All such technology is SCI-classified top secret, and is used solely by the SGC and its SG teams, or in Atlantis.

The humans of Earth (known as the Tau'ri to the Goa'uld and Jaffa, and the Atlanteans to the Wraith) have developed many futuristic technologies throughout the course of Stargate SG-1 and its spin-offs. One of the primary missions of the Stargate Program is the acquisition of technologies capable of defending Earth and improving the lives of its inhabitants. Most useful alien technologies brought back by SG teams through the Stargate are studied at the SGC or at Area 51, and reverse-engineered when possible. Earth has also benefitted immensely from collaborations and gifts from its various offworld allies, such as the Asgard and the Tok'ra. Since the discovery of Atlantis in the Pegasus galaxy, Earth has gained a significant understanding of Ancient technology.

Although extinct, the Ancients (originally called the "Alterans", known as "Lanteans" in the Pegasus galaxy) are the most advanced known civilization shown in the Stargate fictional universe.(Except perhaps for the “Planet Builder” from Stargate Universe series) Among their many technological achievements is the Stargate network itself, central to the franchise, and the City Ship of Atlantis, the setting of Stargate Atlantis. Ancient inventions and machines play critical roles in many Stargate stories, including "The Fifth Race", "Redemption", "Lost City", "Reckoning", and Stargate: The Ark of Truth.

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Wikipedia