Types In General
What is an elemental type? Such questions are often asked by up and coming Pokémon Trainers, hoping to grasp the complexities of battle to their fullest (or, perhaps, to avoid battles they cannot win). And it is understandable that they would ask such a question, seeing as how elemental types can often determine the proper response to a Pokémon. The aspect that confuses them the most is the split between elemental Pokémon and elemental moves; the purpose of this article is to clarify such confusion.
Elemental Pokémon
A Pokémon's elemental affiliation is determined by a combination of physiological and behavioral traits. Fire-type Pokémon, for instance, near universally have internal glands which produce flammable substances alongside specialized organs to direct them; the few Fire types that don't have this operate by redirecting ambient heat in a manner similar to their gland-based brethren, and are thus classified as Fire-type due to their similar behavior. Because their types are determined by their physiology, moves of a specific type will in general have greater or less impact one pokemon of a specific type. In addition, a Pokémon using a move of the same type as its own affiliation will be more adept with it instinctively. Pokémon are generally classified as either "pure", having only one elemental affiliation, or "dual-typed", having two; while many Pokémon could in theory belong to more groups, such metaclassification is generally seen as unnecessary nitpicking by the community.