A theory, often referred to as a hypothesis in its initial stages, is a proposed explanation for a phenomenon based on limited evidence. It serves as a starting point for further investigation and experimentation. Scientists use hypotheses to make predictions that can be tested through research and observation. Once a hypothesis is tested and supported by substantial evidence, it can evolve into a theory. A theory is a well-substantiated explanation that integrates a wide range of facts and observations, such as the theory of evolution or the theory of relativity. Theories are fundamental to scientific understanding and guide future research.