Science is a way "to know" about the natural world and universe. The practitioner of science follows a process of critical and inquiry thinking to explain natural physical processes. The scientific way of knowing about the world requires that scientists make inferences, or conclusions, based on all the available evidence. It is the nature of science that inferences will change, as more evidence becomes available. This gives humans a continuous and increasing knowledge base about the natural world.
Because inquiry and certain methods are following in acquiring evidence, science best answers questions, or statements about the natural world that can be tested as to their validity (hypotheses). Once a body of evidence from many experiments has been developed, an explanation or conclusion is made, which is based on the evidence. This explanation, which is called a theory is not a guess, because a theory encompasses a large body of knowledge and evidence. A theory provides a basis for applying scientific knowledge to solve problems and is powerfully predictive in nature, thus allowing science to build on and refine understanding about the natural world.
A scientist follows a certain kind of inquiry thinking that involves collecting evidence, organizing knowledge in a systematic ways, rigorously analyzing and being intuitive about knowledge, and making inferences about the knowledge acquired by the inquiry process. Being a scientist is a human endeavor that includes team-work and a formal sharing of information in the form of peer reviewed presentations and writings. The result is a never-ending questioning process that has provided a powerful way to know about the world and a way to solve many complicated problems.