Answer: It includes all matter, like stars and galaxies. The universe also includes all radiation and all other forms of energy. No matter where or when you exist, you are a part of the universe, as is everything you experience. There is nothing outside the universe, because anything that exists is automatically included in the definition of the universe.
Explanation: Everything, the sum of all existence
The universe is literally everything, the sum of all existence. It includes all matter, like stars and galaxies. The universe also includes all radiation and all other forms of energy. No matter where or when you exist, you are a part of the universe, as is everything you experience.
