The Universe is generally accepted to be everything that exists, including all matter and energy.
See main article: Timeline.
Before the beginning of time what existed "before" the universe is unclear, however it was known to be a chaotic realm with no order or substance. ("Chaos")
At some point for unknown reasons, the pre-universe exploded in a cosmic event, the so called "birth of time" now referred to as the big bang, in which all matter and energy was created. In the midst of this mysterious event, the first soul, the Universal Migrator was created. ("Dawn of a Million Souls")