Abydos is the name of the planet which coordinates are the ones on the cartouche that was discovered in 1928 near the Stargate. It is also the nearest planet with a Stargate in the series, but according to the movie, it is located billions of light years away from Earth, in the Kaliam galaxy according to Barbara Shore. (this has been forgotten or deliberately neglected in the series, given that you need eight glyphs to travel from one galaxy to another)

Abydos has three moons and the days are thirty-six hours long. Its Gate is located in a pyramid which is, according to Daniel, a replica from the Great Pyramid in Giza, but it is also a landing site for Ra's vessel. Abydos' Point of Origin actually represents this pyramid and the three moons.

Abydonians come from Earth: Ra once used the Stargate to bring a part of the people he reigned over to this planet, so that they dug out the Naqahdah, the material that he makes his technology up with, and therefore enables him to live endlessly. This ended when the people of Earth rebelled and buried the Stargate.

After Daniel deciphered the abydonian history that was written on the walls of a cave, he explained it to the inhabitants of the planet, and they revolted against the false god. Jack and Daniel finally killed him with a nuclear bomb that was first to destroy the planet, so that the Stargate could be no threat for Earth. Abydonians consider them to be their saviors.

Daniel spent over a year on Abydos, and he discovered an underground room, the walls of which are covered with egyptian symbols. Daniel thought they were a map of the Stargate network in our galaxy and Carter used this data to create a program able to update the coordinates of the Gates in order to take into account the expansion of universe.

Abydos was also the planet where SG-1 found Shifu, the Harsesis child, who had come there as a tornado whispering Daniel's name.