The vast array of creatures is commonly divided into "Generations", with each division primarily encompassing new titles in the main video game series and often a change of handheld platform. Generation I refers to "Red", "Green", "Blue", and "Yellow"; Generation II refers to "Gold", "Silver", and "Crystal"; Generation III refers to "Ruby", "Sapphire", "FireRed", "LeafGreen", and "Emerald"; Generation IV refers to "Diamond", "Pearl", "Platinum", "HeartGold", and "SoulSilver"; Generation V refers to "Black", "White", "Black 2", and "White 2"; Generation VI refers to "X", "Y", "Omega Ruby", and "Alpha Sapphire"; Generation VII refers to "Sun", "Moon", "Ultra Sun", "Ultra Moon", ; and Generation VIII refers to "Sword," "Shield", "Brilliant Diamond, Shining Pearl," and "". Each Generation is also marked by the addition of new Pokémon: 151 in Generation I in the Kanto region, 100 in Generation II in the Johto region, 135 in Generation III in the Hoenn region, 107 in Generation IV in the Sinnoh region, 156 in Generation V in the Unova region, 72 in Generation VI in the Kalos region, 88 in Generation VII in the Alola and Kanto regions, and 89 in Generation VIII in the Galar region.