Final answer:
A hypothesis is a tentative assumption based on what is already known, while a theory is a well-substantiated explanation of some aspect of the natural world based on a body of facts that have been repeatedly confirmed through observation and experimentation.
Step-by-step explanation:
A hypothesis is a tentative assumption based on what is already known, while a theory is a well-substantiated explanation of some aspect of the natural world based on a body of facts that have been repeatedly confirmed through observation and experimentation. The key difference is that theories have a large amount of support and can explain numerous observations satisfactorily, while hypotheses are more specific and are used to test specific aspects of a theory.