science, any system of knowledge that is concerned with the physical world and its phenomena and that entails unbiased observations and systematic experimentation. In general, a science involves a pursuit of knowledge covering general truths or the operations of fundamental laws.

Science is the pursuit and application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence.

Science aims to build knowledge about the natural world. This knowledge is open to question and revision as we come up with new ideas and discover new evidence. Because it has been tested, scientific knowledge is reliable. Scientific ideas are absolute and unchanging.

Science can be thought of as both a body of knowledge (the things we have already discovered), and the process of acquiring new knowledge (through observation and experimentation—testing and hypothesising).