Generation I refers to the first group of Pokémon introduced in the Pokémon franchise, which debuted in 1996. This generation includes 151 species, starting with Bulbasaur and ending with Mew. The games were originally released on the Game Boy and laid the foundation for the Pokémon series, establishing core gameplay mechanics like capturing, training, and battling Pokémon. The main titles of Generation I are Pokémon Red, Pokémon Green (released only in Japan), and Pokémon Blue. These games introduced the fictional region of Kanto, where players embark on a journey to become Pokémon Champions by defeating Gym Leaders and the Elite Four.