The universe is everything that exists — all of space, time, matter, and energy. It includes stars, planets, galaxies, and even the empty space between them. Scientists believe the universe began with a huge explosion called the Big Bang around 13.8 billion years ago. Since then, it has been expanding and changing. The universe is so big that we can only see a small part of it using telescopes, and there are still many mysteries we are trying to understand, like dark matter and dark energy.

MY NOTES:

The universe is the vast space that holds everything — stars, planets, galaxies, and all forms of matter and energy.