The Pokédex is a feature that contains a list of all Pokémon that the player has captured and a brief description of each Pokémon. It also displays heights, weights, Pokédex numbers, and models of the Pokémon that have been registered. It can be accessed by pressing a certain key ('I' by default). Pressing this key on a previously unseen wild Pokémon will cause its name to be recorded to the Pokédex. To register the Pokémon's complete data, it needs to be obtained (by capture, evolution, trading, etc.).
If in Creative mode, the Pokédex lists all available Pokémon.