Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence for scientific reasoning is tens of thousands of years old. Science is defined as the observation, identification, description, experimental investigation, and theoretical explanation of natural phenomena. Is also known as the study of the nature and behaviour of natural things and the knowledge that we obtain about them. A science is a particular branch of science such as physics, chemistry, or biology. Physics is the best example of a science which has developed strong, abstract theories. ... the science of microbiology.