The Simulation is the world of the Locked Out series. It is a computer model of the world created by G.O.D. and is ran by Jesus. The Simulation was designed to mimic modern day Earth and was inhabited by artificial intelligence and humans who were using it while in cryosleep. Eventually the program that ran The Simulation was shut down and everyone and everything in it was destroyed. The experiment was meant to go on for 2017 simulated years.
The Vortex is a part of The Simulation that acts as a stasis. It is an infinite wormhole of code that is impossible to enter or exit without direct intervention from a developer or coder of The Simulation.