The Water-typePokémon live in and around water, and their powers are directly related to their habitat system. They have a disadvantage against Electric-types (because water conducts electricity) and Grass-types (because grass absorbs water) attacks. They are advantageous against types such as Fire(Because water puts out flames),Rock(Because water degrades rocks) and Ground(Because water turns dirt into mud) . Water is the type with the most Pokémon, with over a hundred Pokémon in that type altogether.
Water type Pokémon have a massive bio-diversity, possibly because they have the largest and most varied habitat e.g. seas, lakes, rivers and ponds. Most water type Pokémon seem to be based on fish, aquatic mammals, and crustaceans.