Theory: When a hypothesis is given a repeated exposure to experimentation and is not falsified, then it is called theory.
When a hypothesis has been proved by consistent results it becomes a theory. The hypotheses that stand the test of time (often tested and never rejected), are called theories. A theory is supported by a great deal of evidence.
Scientific Principal or LAW:
When a theory can explain many natural phenomena and consistently supported by experiments, and also universally accepted by scientists it becomes a scientific principal or Law.