PID (Pokémon ID) is a unique 32-bit number assigned to each Pokémon when it is generated in the Pokémon games. This identifier determines many of the Pokémon's individual attributes, such as gender, ability, nature, and whether it is shiny. The PID is essential for distinguishing between Pokémon of the same species and level, ensuring each one is unique. It also plays a role in certain game mechanics, like breeding and legality checks in competitive play. Because it is randomly generated, the PID adds an extra layer of individuality and security to each Pokémon, making it difficult to create illegitimate or cloned Pokémon without detection.