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, models of the Pokémon that have been registered, spawning biomes with their conditions, alternative forms and types. 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.).
Trivia
Before Pixelmon Mod 7.0.7, the Pokédex used to be autocompleted if the player was on Creative mode.
The Pokédex used to be an item that had to be crafted to be accessed.
This recipe does not work anymore.