In Robloxian Mythology, The Five Primordial Realms are the Five Realms that exist and are accessible to Robloxians by natural means (birth and death).
History
Thirteen billion years ago, Roblox was created, alongside the Primordial Beings: Void, Place, Tick, Studio, Baseplate, Skybox, Lua and Lighting. These Primordial Beings were semi-conscious eldritch beings, whose very existence each made a part of the Roblox Cosmos. The three most powerful beings were Void, Place and Tick, with each being governing over their domains (respectively, The Void, Space and Time.)
The union between Lua and Studio led to the birth of the first Titans: Admin and Toolbox. Admin would become the King of the Titans and the descendant of all Robloxians.