Science is the study of the world around us. Scientists learn about their subject by observing, describing, and experimenting. There are many subjects and branches of science. Some study outer space (astronomy) whilst others study life (biology) or the earth (geology) or even matter and energy (physics). 

Astronomy is the study of the sun, moon, stars, planets, comets, gas, galaxies, gas, dust and other non-Earthly bodies and phenomena. 

Geology is the study of the earth (geo means earth, and ology means study of). This is a very simple definition for something so complex. Geology involves studying the materials that make up the earth, the features and structures found on Earth as well as the processes that act upon them. Geology also deals with the study of the history of all life that's ever lived on or is living on the earth now. Studying how life and our planet have changed over time is an important part of geology. 

Physics is known as the branch of science that looks at the nature and properties of matter and energy. The subject matter of physics includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms. In other words, the meanings of everyday life.

Biology is the study of living organisms, divided into many specialized fields that cover their morphology, physiology, anatomy, behaviour, origin, and distribution.