Team Rocket is the villainous organization led by Giovanni in the original Pokémon games.
In Pokémon Red, Green, Blue, and Yellow, Team Rocket is a criminal group that steals Pokémon and seeks power and profit. Its activities affect several locations, including Mt. Moon, Celadon City, the Pokémon Tower in Lavender Town, and Silph Co. in Saffron City.
Giovanni serves as Team Rocket’s leader while also secretly acting as the Gym Leader of Viridian City. The player eventually confronts him in both roles, linking the game’s criminal plot to its Gym challenge. The anime also features Team Rocket, especially the recurring trio Jessie, James, and Meowth, though their comedic stories differ from the games’ organization.
Later Pokémon generations introduced new villainous groups with different goals and names. Team Magma appears in Hoenn, Team Galactic in Sinnoh, and Team Plasma in Unova. Those groups are easy to mix up, but Team Rocket is the organization associated with the original Kanto games.