The observable universe
What can we see when we look out at space through telescopes from Earth?
Galaxies
Our A cluster of billions of stars, held together by gravity. is the Milky Way. Each spot of light in the picture is a star. Each star might have planets orbiting.
Question
Why is it brighter in the centre of a galaxy?
There are more stars there. Gravity is greater. There could be a black hole there.
The Universe
From Earth, telescopes such as Hubble can see and photograph far away galaxies, nebulae and stars. This is the observable All the energy and matter that exists.. You can learn about it in The Universe.