There are several types of Pokemon, and what type a Pokemon is determines how it will fight in a battle. The Pokemon's type also determines what its strengths and weaknesses are against other types of Pokemon. Some Pokemon may be more than one type. While this can be an advantage, it also means that these Pokemon have more weaknesses in battle.
Bug-type: These are generally arthropod-like Pokemon that include insectoids and arachnids that typically evolve at low levels. They tend to have high speed and fast attack moves (such as Quick Attack and Fury Cutter). But these Pokemon tend to have many weaknesses, including rock, ground, fire, and flying moves. They generally do not make good defensive Pokemon. Some examples of bug-types include Caterpie, Scyther, Wurmple, and Burmy.
Dark-type: The Dark-type was introduced in Pokemon Gold and Silver. These Pokemon are usually associated with darkness and night. Their moves tend to sinister in nature (such as biting, stealing, and taunting). Examples of dark-types include Poochyena, Absol, and Nuzleaf.
Dragon-type: These Pokemon are dragon-like in appearance, although not all dragon-like Pokemon are dragon-type. Dragon-types have few weaknesses; however, they have a weakness to ice that is often magnified by a secondary Flying or Ground type. They have above-average stats that allow them to overpower most other Pokemon. Dragon-type moves involve the use of claws and breath. Most of them that evolve have three evolutionary stages; they tend to reach their final stage at an uncommonly high level. The Dragon-type is also one of the most common types used for Legendary Pokemon. Examples of dragon-types include Dratini, Bagon, and Kingdra.
Electric-type: These Pokemon have a natural ability to generatre large amounts of electricity. They also tend to have a high Speed stat, a respectable Special Attack, and a decent Special Defense. Electric-type attacks can also cause paralysis. This kind of Pokemon are noted for having very few weaknesses; however, they do have a weakness for Ground (which is possibly the second most common Pokemon move). Examples of electric-type Pokemon include Pikachu, Electabuzz, and Pachirisu.
Fighting-type: These Pokemon learn martial arts attacks, such as punches, throws, submissions, and kicks. They also tend to have high Attack. Examples of fighting-types include Machop, Tyrogue, and Hariyama.
Fire-type: These Pokemon are aligned with heat (usually in the form of flames or lava), and they tend to have the ability to breathe fire. Fire-types are immune to the Burn status effect, and they will instantly defrost if affected by the Frozen status effect. This kind of Pokemon tend to have high attacking stats balanced by lower hit points and defensive stats. Fire-types usually make poor defensive fighters, even though they can resist several common attackting types. Examples of fire-types include Charmander, Cyndaquil, Torchic, and Chimchar.
Flying-type: These are Pokemon that fly, resemble birds, or use aerial techniques such as Wing Attack and Drill Peck. The flying-type has never been any species' sole type; a partial exception is Arceus (who has the ability to become any type by holding a special item). Some moves and abilities exist than can cause temporarily cause a Pokemon to be considered a Flying-type while in battle (such as Kecleon's Color Change ability). Flying-type has been combined with every type except fighting at least once. Examples of flying-types include Pidgeotto, Gyarados, Hoothoot, and Beautifly.
Ghost-type: These Pokemon relate to the supernatural (especially in the realm of the dead), and use odd, ghostly moves such as Lick and Confuse Ray. Ghost Pokemon tend to have decent Attack and Special Attack; however, they also tend to have low hit points (for example, Shedinja can only have 1 hit point). Examples of ghost-types include Haunter, Duskull, and Misdreavus.
Grass-type: These Pokemon tend to have abilities and appearances associated with plant life and nature. They can use many hit point-recovery and hit point-draining techniques. Grass-types also have moves which cause various status effects to their advantage. Grass-types are immune to the Leech Seed move. Examples of grass-types include Bulbasaur, Bayleef, Treecko, and Turtwig.
Ground-type: These Pokemon are affiliated with the soil. Their moves generally cause damage by ground movement (and with rare exceptions, sacrifice Special Attack and Special Defense for higher Attack and Defense). They are immune to electric-type attacks. Examples of ground-types include Geodude, Onix, Phanpy, and Marshtomp.
Ice-type: These Pokemon are affiliated with low temperatures. They usually have a high Special Defense statistic and a low Defense statistic; ice-types also have few resistances relative to their weaknesses. Ice-types are all immune to the Freeze condition. Examples of ice-types include Cloyster, Spheal, and Jynx.
Normal-type: These Pokemon usually do not have any of the characteristics assigned to the other types (except in the case of a dual-typed Normal-type Pokemon). Normal can be considered the "default" type and encompass the Pokemon which do not fit into any other types. They are usually mammals or fairy-like creatures. Unusual Pokemon also tend to be normal-types. Their attacks are not particularly effective against any type; however, only a few types have resistance to the normal-types, and even fewer are effective against it. Normal-types can also learn the moves of other types. Examples of normal-types include Jigglypuff, Meowth, Ditto, and Eevee.
Poison-type: These Pokemon have some poison quality about them, and use poison-based moves to make their opponent sick. Some take after venomous reptiles and insects, some are poisonous plants, while some are composed of or emit toxic chemicals. Examples of poison-types include Weezing, Seviper, and Croagunk.
Psychic-type: These Pokemon usually have mental abilities associated with psychics (telekinesis, telepathy, and prescience). Psychic-types tend to have high Special or Special Attack statistics. They are also among the smartest Pokemon. Examples of psychic-types include Starmie, Mr. Mime, Wobbuffet, and Medicham.
Rock-type: These Pokemon are affiliated with rocks and mountains, and usually have bodies that are made of stone. They attack by throwing rocks. Rock-types usually have high Defense at the cost of Speed. Examples of rock-types include Golem, Sudowoodo, Shuckle, and Nosepass.
Steel-type: These Pokemon are made of or coated with a metal that is like steel or iron. These kind of Pokemon tend to possess high Defense and have a very large amount of resistances; however, they have low Speed and average Special Defense. Examples of steel-type Pokemon include Magnemite, Forretress, Aron, and Metagross.
Water-type: These Pokemon are based on aquatic and amphibious creatures. Their powers are directly related to water. Of all the types of Pokemon, the water-types have the most species attributed to it. Examples of water-type Pokemon include Squirtle, Totodile, Mudkip, and Piplup.
There are also Legendary Pokemon, which are rare Pokemon that have unusual or extraordinary powers. Legendary Pokemon include Articuno, Mew, Mewtwo, Celebi, Jirachi, and Deoxys.