The Pokémon universe is a fictional continuity construct that exists in stories and works of fiction by video game company Game Freak. The Pokémon universe consists of numerous regions.
The concept of the Pokémon universe, in both the video games and the general nonfictional world of Pokémon, stems from the hobby of insect collecting, a popular pastime which Pokémon executive director Satoshi Tajiri-Oniwa enjoyed as a child. Players of the games are designated as Pokémon Trainers, and the two general goals (in most Pokémon games) for such Trainers are: to complete the Pokédex by collecting all of the available Pokémon species found in the fictional region where that game takes place; and to train a team of powerful Pokémon from those they have caught to compete against teams owned by other Trainers, and eventually become the strongest Trainer: the Pokémon Master. These themes of collecting, training, and battling are present in almost every version of the Pokémon franchise, including the video games, the anime and manga series, and the Pokémon Trading Card Game.
There are several regions that have appeared in the various media of the Pokémon franchise. Each of the seven generations of the main series releases focuses on a new region. Moreover, several regions have been introduced in spin-off games, and one in the Pokémon anime, though most of these are still within the same fictional universe. Usually, the different regions are not accessible from one another via land (or at all within a single game), with the exception being Kanto, which can be accessed from Johto and vice versa in the Pokémon Gold, Silver, Crystal, HeartGold and SoulSilver versions.