The universe is the entirety of all space, time, matter, and energy, which began with the Big Bang approximately \(13.8\) billion years ago and has been expanding ever since. It is vast and contains everything from subatomic particles to entire galactic clusters, including our solar system and Earth, which are tiny components in the grand scheme. The majority of the universe is made of mysterious dark matter and dark energy, with the visible matter we can see making up less than \(5\%\).