What is the relationship between a hypothesis and a theory?
A hypothesis is just a plausible explanation for an observable phenomenon. This hypothesis can be tested (called hypothesis testing). A hypothesis must be a) falsifiable/disprovable, b) testable, and c) have predictive value. A hypothesis gains validation when there is significant evidence in favor of that hypothesis.
A theory is a hypothesis (or a group of hypotheses) with significantly large amount of evidence (consisting of repetitions of the experimental results in by different groups of scientists). Then the theory is able to explain verified proven facts.