A Fact is a thing that is indisputably the case and is typically proven through evidence.
In a broad sense we can use the word fact to mean truth. In science a fact must be proven true through evidence, but something can have the quality of truth without actually being proven. For instance the theory of evolution could end up being true, although we haven’t proved it. Whether it is true or not exists independent of our ability to prove it so. Thus a fact is “typically” proven through evidence, but is always indisputably the case.
Facts should not be confused with “factoids” (commonly held beliefs) have aspects of truth to them, but are misleading or not entirely true. For the purposes of the site facts should also not be confused with statistics. Statistics are pieces of data, that may or may not be useful when determining truth. For our purposes statistics should be used to help prove something true or false and shouldn’t typically be used as topics. For instance a study could show that “1% of people think a fact and statistic are the same thing”, the underlying factoid derived from that statistic might be “a statistic and a fact are related but separate concepts”. We could use statistics and data from studies to show the factoid to be true or false (or in our cases, fact or myth).
When we rate something a fact on our site we back it up with research and explanations of how we came to that conclusion. If we think a fact is true but misleading, or if new evidence arises that shows us that something thought to be fact was actually myth we will notate that on the article.
For more information on facts see the Stanford Encyclopedia of Philosophy.