Solar System
The Solar System is the gravitationally bound planetary system of the Sun and the objects that orbit it, either directly or indirectly of the objects that orbit the Sun.
Galaxy
A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter.The word galaxy is derived from the Greek galaxias literally “milky”, a reference to the Milky Way.
Science
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
Universe
The Universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy.