There are 8 Pokemon Regions
Over the last 25 years, eight regions have been discovered to correspond with the eight different generations of Pokemon. They are Kanto, Johto, Hoenn, Sinnoh, Unova, Kalos, Alola and Galar.
Each of the eight regions are very different with many unique Pokemon and settings. They are where both the mainstream Pokemon video games and Pokemon anime are take place at different points in time.