The definition of theory

Ok, I was browsing the internet and came across a site that made me confused about the scientific use of the word theory. This has probably came up before, but try to bear with me. According to this site Scientific Theory, Law, and Hypothesis Explained | Wilstar.com, a scientific theory is something that has been proven.
"But in scientific terms, a theory implies that something has been proven."However it says differently in my college physics textbook.
"One important deifference is that science requires testing of its ideas or theories to see if their predictions are borne out by experiment. But theories are not "proved" by testing." "Physics" -by Giancoli page 2The site also makes note that a scientific theory is just a more complicated scientific law. I always thought the main difference is that theories are something that cannot be derived directly from observation, while scientific laws can. IE. Theories are more of a creative inspiration that comes from our minds to explain phenomona.Also i have learned that it is not that simple. I thought there are different degrees in which the theory is credible. Some theories are accepted by most scientists(such as the atomic theory), and some theories that are debated by many scientists(such as the string theory). Well point in being, is this site false, or am i just crazy. I know it's just a kids science site, but my friend tried to use it to tell me i was wrong, and its second on the google search "scientific theories."PS, do you guys think the theory of evolution can be turned into a law after millions of years of observations? That after so long it becomes a direct observation, or is it that theories cannot turn into laws.Another couple examples is the theory of a round earth, it wasnt until we went into space that it became a direct observation.
Or cell theory. we couldn't see cells until we invented the microscope.

Thread moved here from the Proposed New Topics forum.

your physics book has it right, that website has it wrong.as to the every living thing made of cell thoery--we didn't see cells until the microscope was invented, and then, it was a little while after that. thirty, fourty years, I think? anyrate, microscope in 1500s, cells found early 1600s.the theory was made a little bit later (1700s or late 1600s) that all plants, and all animals were made of cells, based off of the fact that everything observed so far had cells.
It was two theories at first, (one for animal, one for plant) but got merged with a couple of other theories into the definition of Life. which today is challenged by the existance of viruses, and what the first life was like. So the definition is still a theory.A theory never does become a law--in fact, laws are explanations of the facts, and explain them--just like a theory. The laws of motion are also theories of motion.The confusion stems from the fact that at one point, Law was used to explain phenomenon, and the convention stuck. What was a law, like the law of gravity, is still called a law, even though it's technically a scientific theory.The round earth theory still only explains why we see the earth as round. It is an interpretation based off of the evidence, and if a new interpretation that was better, or if there appeared evidence that suggests a nonround earth, it will replace the round earth theory. Yep, it's still not a fact that the earth is round. wierd, huh?

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All a man's knowledge comes from his experiences

Ok thanks that explains quite a bit, and that is really weird that the earth is round theory is still not a fact.

Since the earth gets flatened at the poles by is own rotation, it seems that calling a round earth a fact would be a mistake. Besides, there are mountains and other features that don't fit in the round earth theory...