I've decided to post about the Pokemon Regions:
Videogame Cannon Regions:
Main:
-Kanto: (RGBY Region, Reachable in GSC and Rehashed in FRLG)
-Johto: (GSC Region)
-Hoenn (RSE Region)
-Sinnoh (DPP Region)
Other Videogame Cannon Regions
-Orre (Colo/XD, Can trade with Kanto/Hoenn)
-Fiore (Ranger 1, Mentions and Interacts with Sinnoh)
-Alumia (Ranger 2, Mentions and Interacts with Sinnoh)
-Sevii Islands (FRLG, Reahcable after 7th Gym. It's officially a seperate region from kanto because it's called Nanashima-chihō, or Seven Islands Region, in Japan)
Not Videogame Cannon:
-Orange Islands(Created by the Anime Scriptwriters to fill up the period between the Kanto and Johto Sagas)