Final answer:
A scientific theory is a well-established explanation for a natural phenomenon that is supported by a large body of evidence, developed through repeated testing and experimentation.
Step-by-step explanation:
A scientific theory is a well-established explanation for a natural phenomenon that is supported by a large body of evidence. It is not the same as a hypothesis, which is an educated guess. A theory is developed through repeated testing and experimentation, often involving many different scientists who contribute data from their own experiments.
For example, the theory of evolution is supported by a vast amount of evidence from different areas of science, such as paleontology, genetics, and comparative anatomy. It has been tested and confirmed by numerous scientists over many years.
Overall, a scientific theory is considered the most powerful explanation because it is based on rigorous testing, supported by evidence, and has been independently verified by multiple researchers.