The Planes, (or the Great Beyond or the Multiverse) are unimaginably vast and varied. While a topic so broad means that much about the planes is unknown, that which is known is presented below.
The Solar System of Golarion
Click on a feature to learn more.
The Material Plane is infinite in nature or is at least effectively infinite for the majority of its known inhabitants. The majority of the volume of the Material Plane is believed to the be the void known as the Dark Tapestry while the remainder of the known volume consists of stars, planets, and other material bodies such as comets, asteroids, and meteors.
Demiplanes are finite. Most demiplanes are created by powerful magic and often temporary—they are sometimes made permanent by further magical processes—though they may also be created by natural processes. Demiplane discusses the nature and properties of demiplanes.
More information about some of the notable demiplanes can be found here: