The Universe is the vast expanse that includes everything – all matter, energy, galaxies, stars, planets. It is everything that exists.
The Universe originated in a hot, dense state often referred to as the Big Bang, approximately 13.8 billion years ago. It has been expanding ever since.
Galaxies, such as our Milky Way, are vast collections of stars, gas, dust, and dark matter bound together by gravity. Stars, in turn, are responsible for producing light and heat through processes like nuclear fusion. Planets, moons, asteroids, and comets are found within galaxies, orbiting stars.
The Universe is dynamic and constantly evolving. Scientists use telescopes and other instruments to observe and study its various components, seeking to understand the fundamental principles that govern its existence and development over time.