Eternity is the timeline by the God Camera, captured at the start of the higher-level eternity and being at the Timeline or any lower-level of itself. The final-level Eternity is Imitated at The Emulator.
This was named by BeyondGodPpontinent. Some people call this name: "the never-ending timeline".
It is the timeline of The Emulator. It inhabits all of the events and possible timelines of it, and lasts for all of eternity.