Multiverse

"You think you know how the world works? You think that this material universe is all there is? What is real? What mysteries lie beyond the reach of your senses? At the root of existence, mind and matter meet. Thoughts shape reality. This universe is only one of an infinite number. Worlds without end. Some benevolent and life-giving; Others filled with malice and hunger. Dark places, where powers older than time lie... ravenous... and waiting. Who are you in this vast multiverse, Mr. Strange?"

- The Ancient One to Stephen Strange

The Multiverse is the collective term for all parallel dimensions in existence.