The Pokémon series are primarily RPG games, though some may also call them strategy games. The games started on the Game Boy, where their main line of games continues, but have since branched and had spin offs on the Gamecube and Nintendo 64, though none of them were full-fledged RPG adventures in the same tradition as the handheld games.
The series was started by Satoshi Tajiri and his development company, Game Freak, in 1996. The games revolved around a Trainer who caught and befriended creatures called Pokémon in capsules called Poké Balls. By catching many different types of Pokémon, players would train their Pokémon, create a team of 6 with different strengths, and use that team to defeat fellow trainers and Gym Leaders to gain badges. The ultimate goal in the single player of the game is to get all the badges, defeat the Elite Four and become a Pokémon Master.
Creator Satoshi Tajiri was greatly influenced by the time spent in his childhood discovering and collecting bugs, tadpoles, and other small wildlife. He was also influenced by following Ultraman, a superhero show in Japan, where the hero utilizes capsules (Poké Balls) to save the day.
The games were a huge success worldwide, revitalizing the Game Boy handheld, and spawning many more games, as well as numerous manga series and an anime TV show.
By 2005, Pokemon had become one of the biggest media franchises of all time, grossing $30 billion ($45 billion with inflation), from video games, anime, trading cards, and a theme park in Nagoya, Japan.   In 2014, Google launched Pokemon Challenge for mobile phones. 
The main line of Pokémon games are on Nintendo's handheld consoles, from the Game Boy through the Nintendo DS. These always come in pairs: Red and Blue, Gold and Silver, etc. Usually, long after the original 2 versions of the game have come out, Game Freak creates a new, third version that relates to the other two (Pokémon Yellow to Red & Blue). It incorporates some new features, new areas, alterations to the story, and mixes the exclusives from both versions. These three games make up one generation. These are the games, grouped by generation:
- Pokémon Red and Blue - Pokémon Green - Pokémon Yellow
- Pokémon Gold and Silver - Pokémon Crystal
- Pokémon Ruby and Sapphire - Pokémon Emerald
- Pokémon FireRed and LeafGreen
- Pokémon Diamond and Pearl - Pokémon Platinum
One thing to note when it comes to the first generation of games is that the original pair in Japan were Pokémon Red and Pokémon Green. Pokémon Blue was released several years later, with improved graphics and slight tweaks in where some Pokémon could be found. When Pokémon was brought outside Japan, Green was dropped, and the pair became Red and Blue, with both using Blue's better graphics.
Besides the main line of games, there have been numerous console spin offs, as well as unrelated games on the handhelds. The Stadium, Colosseum, and Battle Revolution games are primarily for battling Pokémon in 3D, though each has something else to add, such as mini-games and story modes. There also many other Spin-off series, like Rangers, with its coming second game, Shadow of Almia and the Mystery Dungeon series.
Generation I, sometimes referred to as the color generation, encompasses Pokémon Red, Green, Blue, and Yellow. They are what started the worldwide Pokémon craze, partially due to Ken Sugimori's interesting and original designs for the 151 original Pokémon, and partially due to several of the games' features that were new to the RPG/Strategy genre.
Pokémon Red and Green were released in Japan in 1996. Before then, the concept of character classes and special abilities inherent to each class was a staple of RPGs, along with choosing which you want to use during the game (such as the system seen in the first Final Fantasy). But Pokémon took the concept to a higher level, giving the player 151 Pokémon species to choose from to make up their Pokémon teams, with each belonging to at least one of fifteen overall elemental "types". At the same time, they took a step back with the actual abilities of all those Pokémon—no matter the strength or species of your Pokémon, they can only know a measly four moves at one time. The combination of a complex "rock-paper-scissors" system, plus this move restriction and the numerous moves that Pokémon could learn, made for a playing experience that could last for hundreds of hours.
On top of the basics of the games were two more gameplay features: collecting all 150 obtainable Pokémon, and battling other players using the Game Boy link cable. Combine that with version-specific Pokémon, such as Vulpix, which was exclusive to Green/Blue—as in, uncatchable in Red. These features added another new dimension to RPG games and had a major part in not only Pokémon's success, but perhaps the revival of the Game Boy as a system itself.
The first generation of Pokémon games takes place in Kanto, a "region" of the Pokémon world. It is based on real-life areas surrounding Tokyo. Its resident Pokémon professor is the esteemed Professor Oak. Kanto's three starter Pokémon, offered to you by Oak at the beginning of the game, are Charmander, Squirtle and Bulbasaur. For more information on Kanto, see main article: Kanto.
Generation II follows the story of a brave and youthful boy by the name of Gold (Jimmy in the anime), in the next installment of the famous game Pocket Monsters Gold and Silver; in the land of Johto, even Team Rocket has made plans to take control of Pokémon and use them for their own evil plots, and with Silver on their side, it makes things more difficult, the player can move from New Bark Town, where Gold's loving mother and the local and very experienced Professor Elm lives to many other places surrounded by various events and tasks.
In the improved version called Pocket Monsters Crystal (in Japan, Pokémon Crystal elsewhere), you are able to play as a female character by the name of Marina.
Generation III refers to not only the game Pokémon Ruby and Sapphire, but it also refers to the remake of the very popular game Pokémon Red and Blue renamed Pokémon FireRed and LeafGreen
Pocket Monsters: Ruby and Sapphire
Pokémon Ruby and Sapphire took place in the land of Hoenn. You play as the main character of the game, either a boy named Ruby (also known as Brendan), or a girl called Sapphire (also known as May). Here, (the players character) is a traveling Pokémon Trainer who collects badges as well as Pokémon/Pokémon Data to complete their Pokédex and use for battle so they can also make there way to the Hall of Fame once they have finished the game.
The games had not only a new set of nemeses (Team Aqua and Team Magma), but another distinction between the two titles: your adversary depended on which version of the game you were playing. In Pokémon Sapphire, Team Aqua was trying to raise the sea level by taking advantage of the Legendary Pokémon Kyogre, and in Pokémon Ruby, Team Magma wanted to lower the sea level by taking control of Groudon. However, in Pokémon Emerald, both groups would have to be dealt with.
Pocket Monsters: FireRed and LeafGreen
In this game, you once again play as a revamped version of the well known hero Red (with new clothes and a new purpose) along with a female counterpart named Green (Blue in Japan) both train and travel around, wonder and figure out the region of Kanto to be great Pokémon masters, and as a plus, the player is also able to enter the Sevii Islands and find new Pokémon to enjoy, capture and battle with
Generation IV also widely known as Pocket Monsters: Diamond and Pearl is the latest in a long line of Pokémon storylines, with the leading hero, Diamond (known as Lucas in the U.S. and Koki in Japan) and the main heroin Hikari (Dawn in the U.S.) as the adventurous, new Pokémon trainers, as they travel through the land of Sinnoh they find many new faces including Pearl, who happens to be Diamond's best friend; They also meet up with Team Galactic who seeks what their predecessors tried to do, with new friends joining you in your quest to be the best.
There are #387 to 493 Types of Pokemon in found Generation 4
- Pokémon - An explanation of what a Pokémon is.
- Pokémon Trading Card Game - Information on the Trading Card Game.