The terms "space" and "universe" are related but have distinct meanings in the context of astronomy and cosmology.
Space generally refers to the vast expanse that exists beyond Earth's atmosphere. It encompasses the three-dimensional realm where all celestial bodies, such as stars, planets, galaxies, and other cosmic objects, are located. Space is essentially the physical extent or the emptiness in which these objects exist and interact.
On the other hand, the universe refers to the entirety of all matter, energy, and physical laws that exist. It includes all galaxies, stars, planets, interstellar space, and everything that can be observed or inferred. The universe is often described as the totality of space and time, encompassing all dimensions, particles, and forces.
The universe is commonly understood to be a vast, expanding entity, which we believe began with the Big Bang approximately 13.8 billion years ago. It continues to evolve and expand, with galaxies moving away from one another due to the expansion of space itself.
In summary, "space" refers to the expanse beyond Earth's atmosphere where celestial objects reside, while the "universe" refers to the entirety of all matter, energy, and physical laws, encompassing everything that exists, including space itself.