Definition of "Fact" :
noun: a piece of information about circumstances that exist or events that have occurred
"First you must collect all the facts of the case."
noun: a concept whose truth can be proved
"Scientific hypotheses are not facts."
noun: a statement or assertion of verified information about something that is the case or has happened
"He supported his argument with an impressive array of facts."
noun: an event known to have happened or something known to have existed
"Your fears have no basis in fact."