"SG-1" is a science fiction television series that premiered in 1997. It follows a team of military personnel and scientists who explore other planets through a device called the Stargate. The team, known as SG-1, is tasked with protecting Earth from alien threats while seeking new allies and technologies. The main characters include Jack O'Neill, Samantha Carter, Daniel Jackson, and Teal'c. Together, they encounter various alien species, including the antagonistic Goa'uld. The show combines action, adventure, and mythology, becoming a significant part of the Stargate franchise, which includes movies and spin-off series.