In simplest terms, Science is the study of everything we see (and we don't see). There are various specialization within science and they deal with physical, chemical, biological and technological aspects. Science includes study of physical (non-living) world which consists of our entire universe, galaxies, planets, solar system, seasons, soil, etc. The chemical aspects of science deal with chemistry and chemical reactions. The biological sciences deal with life, including various life forms (past and present and future), their life processes and related aspects. The technological science deals with the technological marvels we see around us, including transportation means (airplanes, trains, vehicles, etc.), communication devices (cellphones, etc.), amenities, etc.
Science also includes the study of scientific methods, including hypothesis formation and testing, experimental methods and scientific ethics.
Hope this helps.
Science is defined as the pursuit of and application of knowledge and understanding of the world, natural and social after following a systematic methodology based on evidence.