Simulation theory claims that it is more likely than not that we are living in a highly sophisticated computer program, one that provides us with the illusion that we exist in a natural world governed by the laws of physics. The evidence, they say, is all the crazy things around us, the stories we see in the news or on the internet that make us say, “That can’t be real” or more specifically, “I guess there’s a glitch in the simulation.” 
According to some interpretations, there’s no way for us to tell for sure whether the world around us, and the very paths out lives take are real, or subroutines in a vast and complicated computer game.